Activities / sports for 4 year olds?

[~me~]

My DS1 does TaekwonDo, he is 8yrs old. There is Pee Wees that start at around 4yrs old. It's a big group as the Taekwondo Master is very strict and the kids follow instructions and love the organisation of how the group runs.
I was going to put my DS2 in, he has just turned 5, we had TT training issues when he was 4yrs so I am going to start him this term.
Gym Monkeys is another good one for little one's. It's a little kids gymnastics, very popular here and teaches them balance.

[sconeonamission]

J does gymnastics and when he's 5, I'll be signing him up for little A's.

[RhiChiChi]

There is a sporting activity called Ready Steady Go! My gf son used to do it and from what I understand they learn all different types of sports ie: cricket, AFL, soccer etc...