As of yesterday, I'm 25. It was a fun day of hiking, drinks, video games, and district9.
In gdkrecord, I added recording of GdkWindow sizes and exposure areas so that I can troubleshoot some pesky drawing problems with a few custom widgets.

And HTML5 Video below or at http://www.youtube.com/watch?v=XdOLjd52R4E.
Usage:
./gdkrecord-tool exposures myrecordfile.out

Comments (3)
Isn’t this the same as gdk_window_set_debug_updates ?
The main difference is being able to do it after the program has completed running.
Oh, and you can do it for programs that don’t pass argc/argv to gtk_init (such as most mono apps) since you hijack the main loop.