The video below is really cool, although it resembles a bunch of glow-in-the-dark ants crawling around until you realize what it really is. The video is actually a timelapse depicting a day in the life of Washington, D.C.’s Metro system.
The video shows Metrorail, Metrobus and D.C. Circulator activity on a weekday, spanning a 24-hour period beginning and ending at 4 a.m. It’s cool because you can see the systems and the region slowly come to life, achieve a recognizable form and slowly fade away.
I'm not sure why you chose to highlight Washington D.C., but those folks have posted about 30 videos, including one of Spokane Transit. http://www.youtube.com/watch?v=1kDmI4r5ALI
Thanks, I'll post the Spokane one to the front page. That was the one that someone emailed to me and I didn't read the fine print at the time to see that there were videos of other community's transit systems as well.