I saw some news stories recently about new LED pulse technology being developed by Intelligent Optical Systems for the U.S. Dept of Homeland Security to disorient and incapcitate suspects. According to the stories, the rapid light pulses change in duration and color to cause disorientation and nausea. Obviously not intended for civillian use, but interesting technology anyway.
http://www.abcnews.go.com/Technology/story?id=3450394&page=1
http://www.abcnews.go.com/Technology/story?id=3450394&page=1
