My new seat post - 360° electroluminescent light, it turned out brighter than I thought and bluer than I thought (it was meant to be white). I am quite surprised just how bright it is in moderate light.

Some pictures with the thing switched off - kind of looks pale pink when switched off, some with it switched on with the room lights on, then with the room lights dimmed and one in total darkness.

It's not quite finished as I am making a smaller inverter/power source based on those little 3V button batteries so I can shove it down the seat post - at the moment I am driving it from the 6V that I get from the little inverter which you can see on the saddle (which does just about fit under the saddle).