New Scientist has an interesting article on shape shifting robot forms from magnetic swarm [1] which describes multi-robot (swarm robotics) research going on at CMU and other places. The video is pretty neat too:

I also noticed this quote:

But software, not hardware, may be the biggest challenge facing researchers working on swarms of robots, he [Alan Winfield] says: "Right now we just don't know how to design a system that produces complex overall behaviours from a group of simple agents."

Luckily for them, that is exactly the problem that multiagent researchers have been tackling for over a decade. Unluckily, it is a hard problem to solve, at least for some definitions of "complex ".