Nanomedicine Art Gallery
Foresight Institute's art gallery shows artists renderings of nano-scale medical robots.
http://www.foresight.org/Nanomedicine/Gallery/

The Art of Motion Control
This site suggests that motion control is also an emerging medium for artistic expression. Gallery of robots, industrial equipment, and other kinetic devices which are either used to create art or are themselves art.
http://www.taomc.com/

Clayton Bailey Robot Sculptures
Artist, Clayton Bailey has made more 100 life size metal robots made from scrap. Site includes many photos.
http://www.claytonbailey.com/robogroup.htm

Brotron Weapons
Giant robots, atomic weapons, Brotron death rays, and other atomic age sculpture by artist Greg Brotherton
http://www.brotron.com/

Robotic Art of Carl Pisaturo
Robotic Sculpture, built by Carl Pisaturo. Pictured and described.
http://www.carlpisaturo.com/

OmniCircus Junkyard Cabaret and Robot Ensemble
An experimental, surreal musical-cabaret group, led since its founding in 1988 by composer-artist Frank Garvey. Shows integrate live performance with life-sized computer-controlled robotics and midi-controlled virtual-reality (VRpit) performers.
http://www.omnicircus.com/

F18 Institute
An artist coop that works with robotic, mechanical and electronic devices. They re-invent and dismantle existing technology with an artistic approach. Their goal is understanding of the relation between man and machine and man and systems.
http://www.f18institut.org/

Ullanta Performance Robotics
A theater troupe in which the actors are autonomous robots. The troupe presents traditional plays, performance art pieces, and dances; and, for recreation, participates in RoboCup robotic soccer competition.
http://www.ullanta.com/ullanta/