Exercise Ball?

By now everyone's seen these things. I use them at the gym as part of workouts, but more and more, I've seen people around the office use them as chairs while they work, and I'm seriously considering it myself.

They're supposed to force you into good posture, something I majorly struggle with. I'm only 24, and I've had back and neck issues for a while (more on dislocating my ribs in a future post). I figure they're only going to get worse as I get older and spend more and more of my working life hunched over a desk (I've been working full--time for almost two years now, and before that I spent my waking hours hunched over computers and text books at SITE at the U of O, so not a lot of "good" sitting happening here).

My justification for getting it is that I figure I sit for so long at work that no matter what good ergonomic chair I have, I end up slouching. I end up doing at 40 hours of slouching a week, which is not cool, but if this ball was my chair, and I slouched, I'd just fall over, thus forcing me not to get complacent with my posture once I got caught up in some diagram or document or report. And if the experiment fails miserably, I'll just go back to my chair and take the exercise ball home for my modest home gym...

So, opinions? Do you think I should even try this, or is it an unworthy failed experiment?