I took a bunch of art classes a few years back. Most of my video work from that time makes me cringe, but this I'm still pretty happy with.
It's a technical study. I drew maybe thirty pictures of my hand, moving very slowly from one gesture to another, scanned them, and then traced over I think 17 of them in Flash. I tried to do it with tweens, but it didn't work. I did it in After Effects just fading quickly from each hand-drawn original to the next, but the differences in the scans, differences of lighting and paper texture mainly, borked the result. I wanted consistency. So I hand-drew every frame on top of the scans of the original drawings.
After this I did some research on animation, and it seems the workflow in most Hollywood cartoons is to draw keyframes in the States and outsource the hand-drawn tweening to Asia. This leads me to believe that in about ten years (very roughly) we'll see an explosion in home-grown animation. Flash is almost good enough to do the in-between drawing automagically, but not quite. The AI necessary to automate that grunt work is definitely achieveable, however.