From New Scientist:
Thousands of miniscule wireless sensors, or "smart dust", could one-day be used to explore other planets, swirling across the landscape by subtly altering their shape. At least, that's the exotic vision put forward in new computer simulations.
Several different research groups are developing tiny smart dust devices. Each is a few cubic millimetres in volume and can perform simple sensing tasks and relay messages to other such devices over distances of less than a metre. Together, they can be sprinkled across an area or throughout a building, and used to sense chemicals or vibrations, and relay messages from one another back to a central control.
John Barker, an electronics researcher at the University of Glasgow in the UK decided to investigate whether a cloud of similar smart dust "motes" could navigate across the surface of Mars from one point to another, simply by modifying their shape.
On the positive side, this sounds like a memetic introduction to the concept of "utility fog" as envisioned by nanotech researcher J. Storrs Hall (a member of CRN's Global Task Force). The recognition that "smart" millimeter-scale devices might be constructed, networked, and programmed to operate in coordination with each other is a big step toward accepting the idea that smaller such machines should be possible too, from microscale on down to nanoscale.
On the negative side, there is a worry that readers of Michael Crichton's Prey might see these hypothetical devices as a step toward the malevolent (if implausible) demons conjured up in that disappointing novel.
(H/T to KurzweilAI.net)
UPDATE: Here is a BBC article with more details about the planetary-exploring smart dust concept.