I have a Wacom Intous 3, bought 2 years old, absolutely the best investment I made related to computer accessories ever. Simple to use, Lemur, who is three draws and paints extremely well for her age and goes to nick jr with it all the time, I use it for just about everything.
Wacom has several models, and they can be found on ebay (I guess when folks go up a size or two, they sell them, as they never seem to fail).
I like the 5x7, I think that is what it is, not to cramped, packs along with the laptop.
SeerBlue