An industrial designer has taken a shot at designing some nanobots: http://www.coroflot.com/public/individual_file.asp?portfolio_id=337714&individual_id=124392&sort_by=1&
These are apparently going to be used in a film, and are (for now) just 3D rendered images. Not sure how realistic these really are… but they really do have that sleek semi-consumer electronic, quasi dangerous look about them. Sorta like a cross between the Terminator and a Robosapien.