
I just bought a 1-watt LED light (like a Laser, that), and threw a big blinky taillight on the saddle, while I had a helmet (yes), and a reflective vest on. I also wore long pants and a long sleeved track top. Unusual for me to ride in weather this cool (it's rarely cold here).
Well, it was a blast - I forgot how much fun night riding is. The heavy tires on The Clunker made me feel pretty safe, no matter what crap I ran over. The only negatives on the ride were a couple of cars that crowded me a little.
Single-speed city bikes are a good fit for urban riding - big fun!