Juggling is a great way to develop hand independence that doesn't require Bach, sheet music, or even a piano!
Come on, why you people so bad? Why is the whole world joking about me and my things???
I strongly suspect he's NOT joking. Anyway, if you want another suggestion, try playing waltz rhythm in the left hand, and 4/4 in the right (both at the same tempo, so your second left hand bar starts at the same time as the fourth beat of the first right hand bar, etc).
I wasn't joking... and I'm definitely not bad. Many people, in fact, consider my work to be quite good! Juggling is really good for hand independence!
Ok, bye