http://www.flyinmiata.com/Store/images/revlight.gif
Got a Revlight for X-mas and installed it last night. Very cool. It has 11 LEDs that can be programmed to light up cumulatively, one at a time or all together as a shift light. It also has a light sensor built in to auto-dim them at night. Install took about 30 minutes. I have it set cumulatively like above and it works really well.
http://www.flyinmiata.com/Store/images/23-96300-2.jpg