The AP incubator looks sweet, I'm hoping to get one later this year (I'll do a full write up/review if/when I get one)... many people on this site build their own. (usually out of an old fridge or the like)
There are a few good threads on these:
http://ball-pythons.net/forums/showt...ator-Tutorial.
http://ball-pythons.net/forums/showt...oler-incubator