Hard not to like usage of hardware in ways the vendors never anticipated. That said, I'm a little disappointed with 57bpm. I've decided I must have got a little excited.
Is this genuine?! I wouldn't have thought that the sensor in the camera would be sensitive enough to pick up minute changes like that, unless some kind of military-grade light was shining through your finger.
Me and a coworker tried it and also measured our heart rates by hand. It seems to be pretty accurate. I have a HTC Desire and he has a Hero.
military-grade light
Hmm... I'd like to see this tested with consumer- and enterprise-grade light too. ;)