Jesse Sullivan has two prosthetic arms, but he can climb a ladder at his house and roll on a fresh coat of paint. He's also good with a weed-whacker, bending his elbow and rotating his forearm to guide the machine.

When you first meet Steve Mann, it seems as if you've interrupted him appraising diamonds or doing some sort of specialized welding. Because the first thing you notice is the plastic frame that comes around his right ear and holds a lens over his right eye.

By BRIAN BERGSTEIN TORONTO (AP) -- When you first meet Steve Mann, it seems as if you've interrupted him appraising diamonds or doing some sort of specialized welding.