I would probably take better much care of my body if I had implanted sensors giving me live feedback of my body's vital stats and I could earn points and achievements for improving things.

I could have cool apps on my phone that would show my numbers in little charts and dials and stuff.

Blood pressure, heart rate, blood levels of various chemicals, etc.

I don't know if it would work, but it would be awesome if it could tell me how many calories I'd consumed, grams of fat, etc. Basically I'd have a little chemical lab in my body running tests all day.

"Click here to post today's urinalysis results to Facebook!"