He invented the Segway. As we all know, an incaclulable boon to mankind. Lately, he's been wasting his time inventing a machine that purifies water, generates power, and runs on cow shit. Lame, I know.
http://dvice.com/archives/2008/04/dean_kamen_unve.php
http://dvice.com/archives/2008/04/dean_kamen_unve.php