Door Gym (i.e. chinup bar)
 

Hey, anyone have experience with the Door Gym (see http://www.karatedepot.com/tr-ex-25.html ). Looks like a non-marring way to get a chinup bar, but I hadn't heard of it until I read something in a book. We rent, so this would be great if it actually works (and doesn't dump you on your butt). :) Of course I'd have to work up to actually being able to do chinups then :?: