Great news from MIT, Cornell Univ. and GT. They use youBots to assemble complex structures in multi-robot cooperation. In one of the projects, the youBots built a mock-up model of MIT Building 10, in another one, they worked together moving furniture co-operatively, synchronized via wi-fi. 

Video of the youBots building the mock-up model

Video of the youBots moving furniture

Video of the torsion gripper for the youBot.