diff --git a/gui_canvas.c b/gui_canvas.c
index 8a52397..8d7f0f5 100644
--- a/gui_canvas.c
+++ b/gui_canvas.c
@@ -52,7 +52,7 @@ static struct inst *selected_before_drag;
 
 static void update_zoom(void)
 {
-	status_set_zoom("x%d", draw_ctx.scale);
+	status_set_zoom("Zoom factor", "x%d", draw_ctx.scale);
 }
 
 
@@ -61,18 +61,21 @@ static void update_pos(struct coord pos)
 	struct coord user;
 	unit_type diag;
 
-	set_with_units(status_set_sys_x, "X ", pos.x);
-	set_with_units(status_set_sys_y, "Y ", pos.y);
+	set_with_units(status_set_sys_x, "X ", pos.x, "Absolute X position");
+	set_with_units(status_set_sys_y, "Y ", pos.y, "Absolute Y position");
 
 	user.x = pos.x-user_origin.x;
 	user.y = pos.y-user_origin.y;
-	set_with_units(status_set_user_x, "x ", user.x);
-	set_with_units(status_set_user_y, "y ", user.y);
+	set_with_units(status_set_user_x, "x ", user.x,
+	    "User X position. Press SPACE to zero.");
+	set_with_units(status_set_user_y, "y ", user.y,
+	    "User Y position. Press SPACE to zero.");
 
 	if (!selected_inst) {
 		diag = hypot(user.x, user.y);
-		set_with_units(status_set_r, "r = ", diag);
-		status_set_angle_xy(user);
+		set_with_units(status_set_r, "r = ", diag,
+		    "Distance from user origin");
+		status_set_angle_xy("Angle from user origin", user);
 	}
 }
 
diff --git a/gui_frame.c b/gui_frame.c
index 81fb8a5..7eafcd5 100644
--- a/gui_frame.c
+++ b/gui_frame.c
@@ -541,8 +541,8 @@ static void edit_var(struct var *var,
 {
 	inst_select_outside(var, unselect_var);
 	label_in_box_bg(var->widget, COLOR_VAR_EDITING);
-	status_set_type_entry("name =");
-	status_set_name("%s", var->name);
+	status_set_type_entry("Variable name", "name =");
+	status_set_name("Variable name", "%s", var->name);
 	edit_nothing();
 	edit_unique_with_values(&var->name, validate_var_name, var,
 	    set_values, user, max_values);
@@ -1336,8 +1336,8 @@ static gboolean pkg_name_edit_event(GtkWidget *widget, GdkEventButton *event,
 	case 1:
 		inst_select_outside(widget, unselect_pkg_name);
 		label_in_box_bg(widget, COLOR_PART_NAME_EDITING);
-		status_set_type_entry("package =");
-		status_set_name("%s", pkg_name);
+		status_set_type_entry("Package name", "package =");
+		status_set_name("Package name (actual)", "%s", pkg_name);
 		edit_nothing();
 		edit_name(&pkg_name, validate_pkg_name, NULL);
 		break;
@@ -1465,10 +1465,13 @@ static void unselect_frame(void *data)
 
 static void edit_frame(struct frame *frame)
 {
+	const char *tip;
+
 	inst_select_outside(frame, unselect_frame);
 	label_in_box_bg(frame->label, COLOR_FRAME_EDITING);
-	status_set_type_entry("name =");
-	status_set_name("%s", frame->name);
+	tip = "Frame name";
+	status_set_type_entry(tip, "name =");
+	status_set_name(tip, "%s", frame->name);
 	edit_nothing();
 	edit_unique(&frame->name, validate_frame_name, frame);
 }
diff --git a/gui_status.c b/gui_status.c
index de624dc..103cb81 100644
--- a/gui_status.c
+++ b/gui_status.c
@@ -71,24 +71,26 @@ static GtkWidget *status_msg;
 static GtkWidget *status_entry_x;
 
 
-static void set_label(GtkWidget *label, const char *fmt, va_list ap)
+static void set_label(GtkWidget *label, const char *tooltip,
+    const char *fmt, va_list ap)
 {
 	char *s;
 
 	s = stralloc_vprintf(fmt, ap);
 	gtk_label_set_text(GTK_LABEL(label), s);
+	gtk_widget_set_tooltip_markup(label, tooltip);
 	free(s);
 }
 
 
-#define	SETTER(name)					\
-	void status_set_##name(const char *fmt, ...)	\
-	{						\
-		va_list ap;				\
-							\
-		va_start(ap, fmt);			\
-		set_label(status_##name, fmt, ap);	\
-		va_end(ap);				\
+#define	SETTER(name)							\
+	void status_set_##name(const char *tooltip, const char *fmt, ...)\
+	{								\
+		va_list ap;						\
+									\
+		va_start(ap, fmt);					\
+		set_label(status_##name, tooltip, fmt, ap);		\
+		va_end(ap);						\
 	}
 
 SETTER(type_x)
@@ -111,8 +113,8 @@ SETTER(unit)
 /* ----- set things with units --------------------------------------------- */
 
 
-void set_with_units(void (*set)(const char *fmt, ...), const char *prefix,
-    unit_type u)
+void set_with_units(void (*set)(const char *tooltip, const char *fmt, ...),
+    const char *prefix, unit_type u, const char *tooltip)
 {
 	double n;
 	int mm;
@@ -134,10 +136,10 @@ void set_with_units(void (*set)(const char *fmt, ...), const char *prefix,
 	}
 	if (mm) {
 		/* -NNN.NNN mm */
-		set("%s" MM_FORMAT_FIXED " mm", prefix, n);
+		set(tooltip, "%s" MM_FORMAT_FIXED " mm", prefix, n);
 	} else {
 		/* -NNNN.N mil */
-		set("%s" MIL_FORMAT_FIXED " mil", prefix, n);
+		set(tooltip, "%s" MIL_FORMAT_FIXED " mil", prefix, n);
 	}
 }
 
@@ -157,20 +159,20 @@ void status_set_icon(GtkWidget *image)
 void status_set_xy(struct coord coord)
 {
 	/* do dX/dY etc. stuff later */
-	status_set_type_x("X =");
-	status_set_type_y("Y =");
+	status_set_type_x("Width", "X =");
+	status_set_type_y("Height", "Y =");
 
-	set_with_units(status_set_x, "", coord.x);
-	set_with_units(status_set_y, "", coord.y);
+	set_with_units(status_set_x, "", coord.x, "Width");
+	set_with_units(status_set_y, "", coord.y, "Height");
 }
 
 
-void status_set_angle_xy(struct coord v)
+void status_set_angle_xy(const char *tooltip, struct coord v)
 {
 	if (!v.x && !v.y)
-		status_set_angle("a = 0 deg");
+		status_set_angle(tooltip, "a = 0 deg");
 	else
-		status_set_angle("a = %3.1f deg", theta_vec(v));
+		status_set_angle(tooltip, "a = %3.1f deg", theta_vec(v));
 
 }
 
@@ -831,15 +833,17 @@ void status_begin_reporting(void)
 
 static void show_curr_unit(void)
 {
+	static const char *tip = "Display unit. Click to cycle.";
+
 	switch (curr_unit) {
 	case curr_unit_mm:
-		status_set_unit("mm");
+		status_set_unit(tip, "mm");
 		break;
 	case curr_unit_mil:
-		status_set_unit("mil");
+		status_set_unit(tip, "mil");
 		break;
 	case curr_unit_auto:
-		status_set_unit("auto");
+		status_set_unit(tip, "auto");
 		break;
 	default:
 		abort();
diff --git a/gui_status.h b/gui_status.h
index 133c6b4..8a6db63 100644
--- a/gui_status.h
+++ b/gui_status.h
@@ -1,8 +1,8 @@
 /*
  * gui_status.h - GUI, status area
  *
- * Written 2009 by Werner Almesberger
- * Copyright 2009 by Werner Almesberger
+ * Written 2009, 2010 by Werner Almesberger
+ * Copyright 2009, 2010 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -50,43 +50,34 @@ void edit_x(struct expr **expr);
 void edit_y(struct expr **expr);
 void edit_nothing(void);
 
-void set_with_units(void (*set)(const char *fmt, ...), const char *prefix,
-    unit_type u);
+void set_with_units(void (*set)(const char *tooltip, const char *fmt, ...),
+    const char *prefix, unit_type u, const char *tooltip);
 
-void status_set_type_x(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_type_y(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_type_entry(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_name(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_x(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_y(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_r(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_angle(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_sys_x(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_sys_y(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_user_x(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_user_y(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_zoom(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_grid(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
-void status_set_unit(const char *fmt, ...)
-    __attribute__((format(printf, 1, 2)));
+#define SETTER(name)							\
+	void status_set_##name(const char *tooltip, const char *fmt, ...) \
+	   __attribute__((format(printf, 2, 3)))			\
+
+SETTER(type_x);
+SETTER(type_y);
+SETTER(type_entry);
+SETTER(name);
+SETTER(x);
+SETTER(y);
+SETTER(r);
+SETTER(angle);
+SETTER(sys_x);
+SETTER(sys_y);
+SETTER(user_x);
+SETTER(user_y);
+SETTER(zoom);
+SETTER(grid);
+SETTER(unit);
+
+#undef SETTER
 
 void status_set_icon(GtkWidget *image);
 void status_set_xy(struct coord coord);
-void status_set_angle_xy(struct coord v);
+void status_set_angle_xy(const char *tooltip, struct coord v);
 
 void status_begin_reporting(void);
 
diff --git a/gui_tool.c b/gui_tool.c
index d42781b..69c3025 100644
--- a/gui_tool.c
+++ b/gui_tool.c
@@ -249,18 +249,18 @@ static struct pix_buf *drag_new_vec(struct inst *from, struct coord to)
 
 	pos = inst_get_point(from);
 	to = gridify(pos, to);
-	status_set_type_x("dX =");
-	status_set_type_y("dX =");
+	status_set_type_x(NULL, "dX =");
+	status_set_type_y(NULL, "dX =");
 	/* @@@ use status_set_xy */
 	switch (curr_unit) {
 	case curr_unit_mm:
 	case curr_unit_auto:
-		status_set_x("%lg mm", units_to_mm(to.x-pos.x));
-		status_set_y("%lg mm", units_to_mm(to.y-pos.y));
+		status_set_x(NULL, "%lg mm", units_to_mm(to.x-pos.x));
+		status_set_y(NULL, "%lg mm", units_to_mm(to.y-pos.y));
 		break;
 	case curr_unit_mil:
-		status_set_x("%lg mil", units_to_mil(to.x-pos.x));
-		status_set_y("%lg mil", units_to_mil(to.y-pos.y));
+		status_set_x(NULL, "%lg mil", units_to_mil(to.x-pos.x));
+		status_set_y(NULL, "%lg mil", units_to_mil(to.y-pos.y));
 		break;
 	default:
 		abort();
diff --git a/inst.c b/inst.c
index 92e140c..0aa8eeb 100644
--- a/inst.c
+++ b/inst.c
@@ -1,8 +1,8 @@
 /*
  * inst.c - Instance structures
  *
- * Written 2009 by Werner Almesberger
- * Copyright 2009 by Werner Almesberger
+ * Written 2009, 2010 by Werner Almesberger
+ * Copyright 2009, 2010 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -386,14 +386,14 @@ void inst_deselect(void)
 		gui_frame_deselect_inst(selected_inst);
 	}
 	deselect_outside();
-	status_set_type_x("");
-	status_set_type_y("");
-	status_set_type_entry("");
-	status_set_name("");
-	status_set_x("");
-	status_set_y("");
-	status_set_r("");
-	status_set_angle("");
+	status_set_type_x(NULL, "");
+	status_set_type_y(NULL, "");
+	status_set_type_entry(NULL, "");
+	status_set_name(NULL, "");
+	status_set_x(NULL, "");
+	status_set_y(NULL, "");
+	status_set_r(NULL, "");
+	status_set_angle(NULL, "");
 	selected_inst = NULL;
 	edit_nothing();
 	refresh_pos();
@@ -452,15 +452,17 @@ found:
 static void rect_status(struct coord a, struct coord b, unit_type width,
     int rounded)
 {
+	const char *tip;
 	struct coord d = sub_vec(b, a);
 	double r;
 	unit_type diag;
-	
+
 	status_set_xy(d);
+	tip = "Angle of diagonal";
 	if (!d.x && !d.y)
-		status_set_angle("a = 0 deg");
+		status_set_angle(tip, "a = 0 deg");
 	else {
-		status_set_angle("a = %3.1f deg", theta(a, b));
+		status_set_angle(tip, "a = %3.1f deg", theta(a, b));
 	}
 	if (d.x < 0)
 		d.x = -d.x;
@@ -488,10 +490,11 @@ static void rect_status(struct coord a, struct coord b, unit_type width,
 		r = (d.x > d.y ? d.y : d.x)/2;
 		diag -= 2*r*(d.x+d.y-sqrt(2*d.x*d.y))/diag;
 	}
-	set_with_units(status_set_r, "d = ", diag);
+	set_with_units(status_set_r, "d = ", diag, "Length of diagonal");
 	if (width != -1) {
-		status_set_type_entry("width =");
-		set_with_units(status_set_name, "", width);
+		tip = "Line width";
+		status_set_type_entry(tip, "width =");
+		set_with_units(status_set_name, "", width, tip);
 	}
 }
 
@@ -578,8 +581,11 @@ static void vec_edit(struct vec *vec)
 
 static void vec_op_select(struct inst *self)
 {
-	status_set_type_entry("ref =");
-	status_set_name("%s", self->vec->name ? self->vec->name : "");
+	const char *tip;
+
+	tip = "Vector reference (name)";
+	status_set_type_entry(tip, "ref =");
+	status_set_name(tip, "%s", self->vec->name ? self->vec->name : "");
 	rect_status(self->base, self->u.vec.end, -1, 0);
 	vec_edit(self->vec);
 }
@@ -814,8 +820,8 @@ static void obj_pad_edit(struct obj *obj)
 
 static void pad_op_select(struct inst *self)
 {
-	status_set_type_entry("label =");
-	status_set_name("%s", self->u.pad.name);
+	status_set_type_entry("Pad name", "label =");
+	status_set_name("Pad name (actual)", "%s", self->u.pad.name);
 	rect_status(self->base, self->u.pad.other, -1, 0);
 	obj_pad_edit(self->obj);
 }
@@ -842,8 +848,8 @@ static struct inst_ops pad_ops = {
 
 static void rpad_op_select(struct inst *self)
 {
-	status_set_type_entry("label =");
-	status_set_name("%s", self->u.pad.name);
+	status_set_type_entry("Pad name", "label =");
+	status_set_name("Pad name (actual)", "%s", self->u.pad.name);
 	rect_status(self->base, self->u.pad.other, -1, 1);
 	obj_pad_edit(self->obj);
 }
@@ -886,13 +892,16 @@ static void obj_arc_edit(struct obj *obj)
 
 static void arc_op_select(struct inst *self)
 {
+	const char *tip;
+
 	status_set_xy(self->base);
-	status_set_angle("a = %3.1f deg",
+	status_set_angle("Angle", "a = %3.1f deg",
 	    self->u.arc.a1 == self->u.arc.a2 ? 360 :
 	    self->u.arc.a2-self->u.arc.a1);
-	set_with_units(status_set_r, "r = ", self->u.arc.r);
-	status_set_type_entry("width =");
-	set_with_units(status_set_name, "", self->u.arc.width);
+	set_with_units(status_set_r, "r = ", self->u.arc.r, "Radius");
+	tip = "Line width";
+	status_set_type_entry(tip, "width =");
+	set_with_units(status_set_name, "", self->u.arc.width, tip);
 	obj_arc_edit(self->obj);
 }
 
@@ -959,9 +968,12 @@ static void obj_meas_edit(struct obj *obj)
 
 static void meas_op_select(struct inst *self)
 {
+	const char *tip;
+
 	rect_status(self->bbox.min, self->bbox.max, -1, 0);
-	status_set_type_entry("offset =");
-	set_with_units(status_set_name, "", self->u.meas.offset);
+	tip = "Measurement line offset";
+	status_set_type_entry(tip, "offset =");
+	set_with_units(status_set_name, "", self->u.meas.offset, tip);
 	obj_meas_edit(self->obj);
 }
 
@@ -1084,9 +1096,12 @@ void inst_end_active(void)
 
 static void frame_op_select(struct inst *self)
 {
+	const char *tip;
+
+	tip = "Frame name";
 	rect_status(self->bbox.min, self->bbox.max, -1, 0);
-	status_set_type_entry("name =");
-	status_set_name("%s", self->u.frame.ref->name);
+	status_set_type_entry(tip, "name =");
+	status_set_name(tip, "%s", self->u.frame.ref->name);
 }