Just another vote for MagicShine - I have one of the 900 lumen models, and another on order. I have found one on high is great for seeing, but I like having more lumens on my helmet. Today I run a cateye on "blink" on my noggin, but will put the new MS on when it comes in. My plan is to run it and the handlebar light on Medium intensity in the dark, and both on flash mode in the daylight. I am totally convinced that the MS on flash mode has made my ride safer in the daytime.

I am new to dark commuting - but I think I like it better than twilight commuting. I have four lights (3 blinking, one steady) on the back, all red, and two headlights, and reflectors. Blinking to be seen, steady (in the case of headlights) to see.

Now just to see how much guts I got for commuting in the cold and wet...