A joystick with a red LED would certainly be an interesting idea though!
Wouldn't it though? *wistful sigh* This is what I mean by the bling factor.
A very late refresh of this thread, because I noticed that Exposure now do rear LED lights.
However, they are not what I would like. They do two models, the
RedEye and the
RedEye Micro. They are both designed to plug into their current generation of front lights (Maxx 2 family), and vamp their power from them. The RedEye has a cable to plug it into any front lights, and the RedEye Micro is designed to plug directly into, for example, a Joystick on a helmet. It doesn't have a cable, so the light has to be positioned so that the front and back lights can both be usefully seen, so a helmet mounting is probably one of the few sensible locations for it.
It's a shame they haven't produced a completely stand alone version. I particularly dislike having to run a cable from a handlebar lights to a seatpost lights, since if you firmly attach it to the tubes, you can often foul brake cable runs (and it looks like the cable is attached permanently to the rear light, so even more problems if you want to remove the light for security).