The Digital Photography School blog has a great beginner's guide to capturing an effect familiar to fans of middle-brow films and photo exhibits—light trails. Any camera with a full-featured "manual" mode that grants exposure control can capture light movement, and the guide helps you plan good trail shots. For instance:
Timing/Light - One might think that the middle of the night is the best time for light trail photography (and it can be) - however one very effective time to do it is just as the sun is going down (just before and after). If you shoot at this time you'll not only capture light from cars, but ambient light in the sky which can add atmosphere to your shots.
With a little practice (and a healthy dose of patience), your street and nightlife photos will stand out. Photo by Waka Jawaka.