I learned about an international animation collaboration project last fall called Rotoball. This was created by a technology/art teacher in Shanghai, China.
I planned on seeing if my oldest students (5th graders) were interested, but by accident I miscalculated clean up time with a group of third graders, so I introduced the project to them with the extra time. They jumped all over it. Rotoscoping is drawing frame by frame over video to create an animation. The Rotoball project weaves 15 second animations together by incorporating a ball that enters from the left, transforms into anything, and exits to the right.
My students spent 2 months of recesses drawing this 15 second animation. Check it out here.
The final Rotoball movie will be shown at the Shanghai Student Film Fest this April.