I remember when Swiss Balls first became popular at the gym I was working at, our party trick used to be doing a front squat on them with a nominal amount of extra weight.
That does not quite compare to this though: Pretty impressive balance and/or lots of patience…
Why not to try this at home (Outtakes):
Ouch.
There are of course a lot of sensible things you can do on a Swiss Ball. If you are in the market for one I would highly recommend an anti burst version. You will pay a little more but I think it is money well spent. I was once working in a gym in Canada when a pro Hockey player training there was doing a lying tricep extension with a fair amount of weight. Just imagine a guy lying on his back on a Swiss Ball with his arms and hands pointing up towards the roof . In his hands was a 30kg dumbbell held straight above his face. If that still does not make sense then similar to the picture on this site, but with more weight. POP! Swiss Ball pops, and he hits the floor, closely followed by the dumbbell into his face. Lots of blood. Buy an anti-burst.