if you happen to be in a major Canadian city or use the interweb for shopping - Mountain Equipment Coop cannot be beat.

I bought a couple of lights for $100 from my LBS - these fell off of my bike and broke and were not very good anyway (Trek.)

Then I bought a rear red flasher LED from MEC for $5 and a front light for $12 and am AMAZED at how well they perform and how long they last and how sporty they are.

Cheers - B