Yes, Apple did it. The integrated a Fingerprint Sensor in the Iphone 5S home button. So what can you do with it? Ofcourse to unlock your iPhone with one touch of your thumb on the sensor. No typing of the passcode anymore yay! Well another example is "Since it's built in, you can make iTunes purchases by using your finger to authenticate." Buying stuff with just your finger dangerous but safe! Dangerous because is it so easy to shop and pay, and safe because you are the only person that can pay. Not your kids after getting your passcode plus your iTunes password :-(.
The sensor is 170 microns thin, 500 ppi resolution, scans sub-epidermal skin layers and has 360-degree readability. "It reads your fingerprint at an entirely new level." via Engadgetpic via engadget