"The next generation of computers will be able to carry out complex calculations but will be little bigger than a snowflake.

Such tiny computers – nicknamed smart dust – would work much like their larger cousins, says Prabal Dutta at the University of Michigan in Ann Arbor. They will have tiny CPUs that run programs on a skeleton operating system and be able to access equally small banks of RAM and flash memory. The plan is for such sensor-packed machines to be embedded in buildings and objects in their hundreds or even thousands, providing constant updates on the world around us.

Dutta's group is creating the first prototypes, which they have dubbed Michigan Micro Motes. These devices, a cubic millimetre in size, come equipped with sensors to monitor temperature or movement, say, and can send data via radio waves."
http://www.newscientist.com/article/mg21829146.400-smart-dust-computers-are-no-bigger-than-a-snowflake.html