Take it one step at a time.
If he wants to self-train for pee, let him. Be aware that he may stop going on his own - he will quickly discover that putting down his toys to pee isn't as much fun as keeping playing. So don't rely on him telling you or going on his own. Keep track and make sure he tries to pee every 2 hours or when he starts to do the "pee pee dance".
If he will only poop in a diaper and never takes it off, consider trying pullups. Usually they are a waste but they may help your little one feel more grown up - he can work them like undies for pee but still have them for poop. Once he is willling to poop on the potty (which could be weeks, months or years away), you can switch him to undies.
at 9:03 PM on May. 2, 2009