Little test using (1) Yongnuo camera mountable LED unit as a key light in a dark room. It has 135 bulbs, dimmable, and pretty darn bright. Light was at about 75% power.
Purchased from eBay, link: cgi.ebay.com/135-LED-Video-Light-SYD-1509-4-DV-Camcorder-Camera-/320624665624?pt=LH_DefaultDomain_0&hash=item4aa6b82418
More info and pics: cheesycam.com/the-next-big-thing-yongnuos-led-video-light/
Video shot with Canon T2i, with Magic Lantern firmware. AGC disabled and audio recorded with Zoom H1 mounted in hotshoe and fed into camera with Sescom DSLR cable. Link: markertek.com/Cables/Audio-Cables/DSLR-Audio-Cables/Sescom/LN2MIC-ZOOMH4N.xhtml?LN2MIC-ZOOMH4N
More reviews and tips: foursandyfeet.com