Series of simple black and white sketch animations as GIFs

I have a series of simple scenarios I'd like to have animated as GIFs (I'm open to alternatives but no flash). Each scenario will be something like "cat walks into room and does X". There are about 6 scenarios at present (maybe 1 or so more depending on how well it comes out). The feel of the animations should be: - Fun - Not too complex - Black and white If you're thinking "something for a children's book" you're going in the right direction.