To me, the biometric readers you see on most laptops are obnoxious blemishes—they really can't make them more discrete? Apple feels the same way, so I like their ideas for seamless biometric security.
The most realistic and likely biometric tool is a hidden sensor within a touchscreen or notebook's trackpad that would detect fingerprints, vein patterns or even the shape of your ear when you use the phone or notebook like normal, making the whole process nearly invisible. The patent also considers face recognition using the webcam—but considering our past experience with VeriFace's tech and iPhoto's face recognition, that sounds kinda lousy. The "ew, creepy" solution they propose is collecting a user's DNA to recognise their genetic makeup when they come into contact with the machine.
Oh and there's a couple of ideas like arranging shapes or patterns that are sorta Android's neato puzzle lock. [AppleInsider]