iPhones and PCs take fitness to heart

New technology turns the iPhone into a heart monitor and fitness tracking system. SM Heart Link, a so-called "wireless bridge," collects data from sensors -- such as heart rate chest straps and cycling sensors on bikes --and sends it to the iPhone for display and tracking. The iPhone can now double as a heart rate monitor and bike computer, tracking and storing workouts and even sending the data to medical assessment websites. This, of course, is not cheap. The applications are free, but the module costs $155. There is also the price of the assessments, the sensors, and the iPhone itself.