The twoddler application is basically a Fisher Price Activity Center enhanced with pictures of family members and friends, and an Arduino board inside. All activities are captured by sensors connected to the Arduino board and are processed in two different ways:

activities are translated into Twitter messages and posted on the toddler's personal Twitter account
activities are send to another Activity Center and will generate effects (e.g. colored lights that blink) on your friends activity center.

research.edm.uhasselt.be/twoddler