I find it really develops your strength and speed and coordination, especially when it comes to all the little muscles in your wrists and forearms...not to mention the bis!

I've tried it with the jab hand but didn't like it. In this case, I'll simply do a 2-handed chest pass against the wall. I also like to plyometrcially push a heavy bag....push it up as high as you can make it go, let it swing down, catch it, and thrust it away from you again. kind of like clap pushups but with a heavy bag. Trust me...these work too! Make sure you keep your elbows tucked in to mimick a punch.

Back to the ball.... since our gym is a bit small with limited wall space, I have to stand about 6' away. But if it's nice out, I'll do it outside out back and stand about 10-15 feet away. (dependng on the weight of the ball of course!)