Need to borrow a bike in DC.... anybody know somebody?

I'm going to DC next Thursday as well as the Thursday-Monday after Labor Day, and it would be reallllly great if I can find a bike to borrow there.  Having four bikes here, renting one anywhere just seems... wrong.

Does anybody have biking friends in DC who might lend me a bike for those two weekends? I'm 5'10" and I'll ride pretty much anything except a recumbent.  Any help would be way way appreciated. I'll buy you beer or bake you a pie.  And I'll buy your bike lending friend beer, too.