In all seriousness, I did go Zorbing once which is sitting in a hamster ball like thing that floats on the water- it-was... AWESOME! You could keep running and running but you would fall over on your face because your legs could never move fast enough, and falling over didn't hurt. You could sit down and just roll around for the lols! xD It was hilarious fun.
I think the more immediate danger was the fact there were no holes meaning after about 6 minutes you'd start breathing in your own Carbon Dioxide before collapsing due to lack of air xD But hey, I lived.