Cole used to be like this - now he is better, although he still goes through phases when he'll take several mini-naps throughout the day. Sometimes he also will take a big 2-3 hour nap around noon, and then not want to sleep for the rest of the day. This would be fine except he's so young, he still really can't go more than 4 hours or so without geting completely overtired. I don't think there's a whole lot you can do - you could try keeping him awake a little longer between naps, but if you overdo it he'll get hyper and not be able to wind down, as I'm sure you know. I have just learned to accept Cole's erratic napping as a fact of life.
: Whenever I feel like I wish he would just take a decent nap already fer Chrissakes, I remind myself that "they" say that kids who don't nap a lot are supposedly very intelligent. Apparently they are not so intelligent that they know they should sleep when they are tired, LOL. Just kidding.