The days are getting shorter and my son had to cycle to his Boy Scout meeting tonight so I bought him the Knog Bullfrog front light. This is my new favorite front light!
It's very bright, attaches easily to any roundish protrusion, and has a very fast flash pattern that I like. I use rechargeable batteries and changing them is a bit of a pain -- you need to slide the whole silicone cover off to get at the batteries -- and I don't know how waterproof this is yet, but so far I'm impressed.
This is a "be seen" light -- it's good for being seen on lit city streets. If you need to light the way to see the road, the Knog Bullfrog isn't the right light for you. Otherwise, though, this thing looks cool and it stands out from the other lighting.