Reelight SL100 on a Raleigh Twenty folding bike
They are a little hard to see here, but I have mounted a set of battery-free induction powered SL-100 Reelites.
The rear light had to be pointed down instead of straight back, due the location of the rack and fender mounts. I thought the light wouldn't be visible like this, but it is. I can see the red light emitted from over a block away.
The lights are bright enough to be seen, and minimally light up the road to see what's in front of you.
The SL-150 model is a bit more advanced, it adds capacitors to the lights so that the beam becomes steady, and the lights stay on a bit longer at stop lights.
Overall, I'm pleased with this self-powered lighting system for $45.