Finally broke down and bought a bike computer (wireless Cateye, total bad ass little tool). We managed to bike 15 miles today (over to the stadium, around the Yards Park, and back to Crystal City) in about 90 minutes (10 mph pace). Call Rizzo - we're ready for the home opener!
Don't forget Beach Drive in Rock Creek Park which is closed on weekends, great ride up to the Md line all uphill, then back downhill return trip.