I commute year round, and the object of my game for night riding is others to be able to see ME.

I have:

Flashing white LED clipped to my helmet visor.
Flashing red LED light clipped to my backpack.
Flashing red LED light attached just below my saddle.
Bar-ends.
"Firefly" valve stem caps, they're Toys, but VERY effective.

I also have a 5w & 10w halogen pair clipped to my bars, one aimed at the road, one aimed at oncoming traffic The battery is made by Nightstick, but for the life of me I can't recall the rest. The battery lasts only about 1.5 hours but I bought it a couple years ago.

If you wait till the end of the season, alot of bike shops put night-riding light systems on special. I got a terrific deal on mine because of that.

There's a joke among some of my friends that I'm lit up like a Christmas tree, but I'd rather get bizzare looks than not be seen. And, at one point in time I actually had a set of battery-powered christmas lights clipped to my backpack, so the joke is half serious.