You can already track heart rates with an iPhone, but what if your phone could alert you to liver failure as well? A Dutch research company has created a system which sends "status updates" from electrocardiogram sensors to Android phones.
A simple dongle that fits into the microSD card slot (obviously not compatible with iPhones, then) receives information from sensors attached to a necklace over the nRF24L01+ frequency, alerting the person to the status of their organs' well-being on their Android. In turn, the information can be sent on to the patient's doctor, so there's no risk that the patient will just ignore the alarm and continue playing Angry Birds.
The Human++ BAN system, made by IMEC, doesn't necessarily have to be outfitted to someone with known medical issues either, with athletes obviously being interested in monitoring their health to improve their workout routines. I just hope these "status updates" are more legible than most tweets or Facebook status updates. [New Scientist]