There are three teams in the District of Columbia (615, 928 and 1446). The Banneker High School team (school web site:
http://benjaminbanneker.org/) would be a great place to help. They are very high on spirit, and short on engineering help. I am sure they would love to have your participation.
There are also 10 teams in northern Virginia and four in the local Maryland area if you can't get linked up with any of the DC teams.
-dave