I love the different sense the city has (I'm a urban night rider). Go downtown to the financial district and all the streets are open and all the buildings sort of channel you in but you're free to go as fast as you like. I love the sparkliness. I love steam coming out of manhole covers. I love watching people do their evening things, going to movies, going to bars and clubs, taking carriage rides.
Biggest don't-likes, idiots (drunken or otherwise) who take the dark as an excuse to endanger me. Period.
I'm a visibility proponent. At night I always got my rear red blinky and my headlight. I don't go overboard, I don't have the dayglo vest with the Scotchbrite stripes or anything like that, but I'm a big believer in active lighting. Way too many fatalities involve unlit cyclists after dark and my own personal experience is that they're hard to see until the last moment, even as a cyclist.
I'd post a more direct link but my server seems to be dead right now. I have a bunch of photos taken at night riding around here:
www.zweknu.org/pics?alb=boston you'll just have to page through some of the thumbnail views to find where the night shots begin.