For one, I'd suggest UberX -- I've heard it's a lot cheaper than even regular cabs, let alone Uber. UberX is sort of like Lyft, where people sign up and use their own cars to cab people around. They're vetted and things, it's not just any person off the street. I haven't used UberX but a few friends love it. And a related note, Lyft is the same idea -- you may have seen their pink mustaches on the front of cars. I also use the MyTaxi app, which works like the Uber app but is for regular cabs. I've had luck with it in the past, and rates are the same as it would be if you hailed a cab on the street.
And when the weather is nicer, there's always Capital Bikeshare, though riding up the hill sucks. The hill is less steep on 11th Street and Georgia Avenue than on 14th and 13th, however.
So those are my suggestions -- how about yours?