Capital Bikeshare, the bike sharing service with some locations in the neighborhood, is now accepting sign-ups. The annual memberships are currently discounted, $50 a year instead of $75, and the first 2,000 folks to sign up get a keychain and t-shirt. There's also monthly memberships for $25 and daily ones for $5.
Basically, you sign up and grab a bike at one of the stations, then ride it around and drop it off at another station. It's free for the first 30 minutes, then they charge you more as you keep the bike longer. In our area, there are bike stations at 14th and Harvard, 16th and Harvard, Park between 13th and 14th, Fairmont and Georgia, and more. The map is below.
There's more details here, and on their website.
View Capital Bikeshare in a larger map