Okay… in 2.25, add a constraint. Then press “Edit IPO” next to that constraint (make sure you have an IPO window open). Now Control+Leftclick in the IPO window to add keyframes. You’ll probably want to change the keyframes to be exactly where you want them by pressing N. 0 is no effect, 1 is complete effect. Just go from 0 to 1 at the moment the character picks up the ball.
Or use the layer IPO technique if you want… but DON’T just keyframe the ball. It looks crappy.