My friend Steve Davee posted this fun project to Instructables. It's a perfect project for shut-in parents and kids to do together.
The main body parts of the bots are keyboard keycaps and Q-tips/cotton swabs. An eccentric weight (pager) motor provides the bouncy movement that makes your vibrobots go.
Dip the swabs in watercolor paints, place the little critter on some paper, and watch your little tabletop Jackson Pollockbot go to town.