http://tesladownunder.com/LEDs.htm#100%20W%20LED
the actual array is available here:
http://cgi.ebay.com/1-PC-BRIGHTEST-1...3A1%7C294%3A50
They consume ~100W, and require a substantial heatsink. These are really designed to be used for streetlights, but the guy who wrote the page at the 1st link actually tried making a bike light out of the thing - kind of as a lark, I guess. He had this funny comment
Above is the LED on my bike with the focusing lens. It makes my very adequate 3 W LED bike headlight look rather puny. It's like having a new weapon on your space fighter. Now, let's go and use it irresponsibly...
The light is bright enough that it is somewhat of a fire hazard..