Was looking for a bike lightset and stumbled onto this Danish-made one. Good for commuting in well-lit areas or just as a backup! Cheapest price online here sold by a bikeshop in Ayrshire I believe. Most online stores are selling them for more than £30.
This lightset uses induction to power it, so there's no batteries involved - just cycle and the LEDs will blink. It has a capacitor built in so the light will run for up to a few minutes at stops.
Not that many reviews on this lightset but I've just received mine and tested it out. Sure enough it works, starts blinking after a couple of seconds pedaling and they're bright enough too (it complies to UK regulations). Of course this lightset is NOT meant to light up your path, just to make drivers aware of you.
One niggling bit I have is it was slightly fiddly to fit, and the magnets have to be so close to each other (1-3mm) they tend to stick when they pass each other - making a very slight thunk-thunk sound as the wheel turns. Although it doesn't affect the lights and maybe it's just my bike anyway, thought you should be aware of this.
*Not compatible with hub geared bikes or Brompton folding bikes.*