Easy to use
Easy to wear
Convenience for the win.
With a GPS inside you will 'warned' when a friend is near, when you should get medicine from a nearby pharmacy, which subway to take, ...
You could communicate with relatives, doctors, ...
Notifications will appear when to take your medicine, when to go to the doctor, ...And the real winner would be to integrate different monitoring solutions. Source: GottaBeMobile -> iPod Nano as a watch is awesome, but does not impress the ladies