Everyone knows passwords suck. iPhone users are about to get a nice alternative: As widely predicted, Apple's new iPhone 5S model includes a fingerprint scanner that provides users with new security features tied to their biometric identity, in a system Apple is calling Touch ID.

The sensor, built right into the Home button, is just 170 microns thick--about three times that of a human hair--and can read a fingerprint with an incredible level of detail, thanks to its 550 points-per-inch resolution and the ability to detect and capture the skin's inner layers for added precision. Thanks to clever programming, the sensor supports multiple fingers, and can recognize a fingerprint regardless of its orientation.

During the iPhone 5S introduction at Apple's special event on Tuesday, company exec Phil Schiller announced that iOS will allow customers to use their fingerprints to unlock their phones in lieu of passcodes, and even to log in to their iCloud accounts without having to type in their passwords--welcome news to anyone who keeps sensitive information on their mobile phone and hates having to deal with constantly typing in passcodes and passwords on a tiny keyboard.