I forgot the picture of the tail light:
http://img408.imageshack.us/img408/2258/tailbh3.jpg
It's 25 very good LEDs in the housing of an old Cateye. There were so many extra lenses in the cover for only 3 LEDs! Now it's more effective... The control circuit is in a small extra box.

It doesn't weight a ton. The main parts of the weight are only the hub dynamo and the battery but I don't care anyway.