Ok, I was just up at a festival where we had waterpistols & bubble guns. (Aside: this combo makes for a great 3D shooting game, better than a playstaion 2).

But, .. here's one for the twirlers.

Get the small waterbomb balloons and try to twirl them with slings, the David and Goliath type. Of course, it's fun to hurl them at your friends too (just fill'em with water, not with rocks).

Have fun.

Firenomad