There are a lot of great programs that make Smartphones the perfect running partner, such as Runkeeper. But if you don’t use an iPhone or Android (or you’re just getting lousy reception), there are online resources that can help take the mystery out of your last trail run. Enter your starting address, zoom in, and plot your course, and walkjogrun.net will let you estimate your distance covered, speed, and even calories burned as long as your route is visible via satellite or documented. On my last Mt Tam run, my iPhone and AT&T logged me in as covering 3 miles over almost two hours of running due to spotty coverage whereas I covered more than 7.