I have used a balance ball at my computer for about a year now and I absolutely LOVE what it's done for my lower back! It honestly has made a big difference. Plus it's fun to bounce around on when I'm listening to music. However, I find that I'm making my mousing wrist VERY sore by pressing on that arm as a means of maintaining my balance, and it's a habit I can't seem to break. I have tendon problems in my wrists already from typing for a living, and I need to be careful with that as I can't retire yet! So I have reluctantly bought myself a standard office chair and I plan on putting a Gypsy sit-upon on my Christmas list so I can get back some of that "wobble and bounce" that I've enjoyed so much from my ball, and hopefully keep my back feeling this good.
I think I'll plunk the ball in front of the TV instead. Who knows, maybe I'll even work out a bit! (Nahhhh)