I definitely affirm dribble tag that Jeff mentioned. It teaches them to change direction, change speed, keep their heads up, all the while trying to control their dribble. And they get some conditioning in. The kids love and I still use it with my 12 year olds (player "it" also must dribble). You can add a few wrinkles like limiting to using their weak hand or use a "freeze" version where if they are tagged they have stand in place pounding their dribble until the coach touches them and "frees" them.