…an idea about how to build robots for various complex tasks. Instead of designing a new and different mechanical robot for each task, you just build many copies of one simple module. The module can't do much by itself, but when you connect many of them together you get a system that can do complicated things. In fact, a modular robot can even reconfigure itself – change its shape by moving its modules around – to meet the demands of different tasks or different working environments.

http://www.parc.xerox.com/spl/projects/modrobots/

Flying Robots