I've commuted and toured at night in the Philadelphia area and NJ. Latest I've been riding is 1:00 AM. When I've been out late I've tried to have lighting serve two purposes:

- be seen
- let me see

To see, I used a Cygolite Night Rover dual beam light on the handlebar, and a Planet Bike helmet light. I might add a cheap light I carry as a backup if I'm concerned.

To be seen, I had a blinker on the back of my rear rack, another on the saddle, and sometimes one on the back of my cycling jacket. (Some people ad another to the back of their helmet. If I was regularly commuting I'd do so too.) If I wasn't wearing my yellow jacket I was wearing a highway safety vest. In addition I might have a small blinker stuck whereever else I could put it. I put black reflective tape on my panniers, my helmet, and even on my shoes.

The effect you want is to cause drivers to slow down as they say "what in the hell is THAT?!?"