We think bicycle wheel-illuminating Revolights look really cool, but at $US220, they’re not cheap. Here’s a DIY version that costs about $US35 for each wheel.
Instructables user Diyler uses reed magnet switches instead of a microcontroller and 18 LEDs powered by two AA batteries for his “Lightrider”. Looks like something you might be able to replicate for safer and more pleasant riding at night.
Lightrider DIY Bike Light [Instructables]