Being able to watch TV or listen to music while you run is one of the major benefits of running on a treadmill. But for those of you who would rather run outside, but can't due to weather or health reasons, you can actually use race course DVDs to simulate the experience.
Outside Interactive has five DVDs, which include Central Park, the Charles River, a 10km course and the Boston Marathon, and are pre-paced with proper mile markers. You can also change your treadmill's incline and speed to match what the real-life course is doing, but since the DVDs don't communicate with your machine, you have to do it manually.
They have a Virtual Runner series that's going to debut this month, but they're not available for purchase yet. And if you're a biker rather than a runner there's a similar Google Street View option for stationary bikes.