I bought a pair of LED stop / tail lights bulbs. They looked really nice with just the tail lights on, but when I put the brake on, they only got slightly brighter. Not safe at all. It's a shame because this design has LEDs pointing towards the reflector as well as straight back. They will get it right at some point I am sure.
http://cgi.ebay.co.uk/NEW-2x18-LED-TOWER-RED-STOP-AND-T...tem#ebayphotohosting