DC Specific: How can I get from Arlington (Clarendon/Courthouse) to Glover Park (north of Georgetown) with public transit?

Did you try the Metro Trip Planner?

Or HopStop.com?

The 30 buses (31, 32, 36) run cross-town from southeast DC to upper northwest. Part of the trip runs up Wisconsin avenue from Georgetown to Friendship Heights metro.

I think the fastest way there from Clarendon would be take the orange line to Farragut west and transfer to a 30 bus in the direction of Friendship Heights. This will take you all the way back through Georgetown, but at least then you only have to take one bus.

You can also catch the Circulator at Farragut West or in Georgetown and this will take you pretty far up Wisconsin but not all the way to Glover Park. They run a lot more often.

Or you can take the metro to Dupont Circle (approx. ½ hour from Clarendon) and take the D2 bus to Glover Park. It will take you down P street then make a right up Wisconsin.

I just use this! http://www.wmata.com/

Put it into Google Maps, and instead of driving click on the little metro icon. This will show you public transit directions.