Workout equipment (bikes, treadmills, rowing machines, etc.) that have virtual reality googles and game controls on the handles.

Imagine actually having to run, ride, or row through a Counter Strike type gun fight. Or having to ride faster and over hills to avoid the cops in Grand Theft Bicycle.

The same machine could be set up for athletes to practice courses and races on a virtual track.

Imagine running the Boston Marathon on your treadmill and actually seeing a digital Boston Landscape while your running.