This prototype Nanorover is only 20 cm (8 inches) long. One possible use for this type of miniature explorer is to send back information from the surface of an asteroid to an orbiting spacecraft. The rover's camera can be focused to take panoramic shots as well as microscopic images. Solar cells will be placed on all sides of the rover so that even if it flips over on an asteroid's low-gravity surface, the rover will always have enough power to activate motors that will allow it to right itself. Wheel struts will allow the rover to position its chassis such that the camera can be pointed straight down at the surface or straight up at the sky.
For more information: http://robotics.jpl.nasa.gov/tasks/nrover/homepage.html
Image Credit: NASA