Fingerprint readers in phones are nothing new, some devices have tried implementing it before. Unfortunately it didn't catch on very well because they weren't all that useful and easy to use.
Apple has implemented a new fingerprint reader in its all new iPhone 5S. Apple are calling it 'Touch ID' and it is placed inside the all familiar home button. Touch ID lets you unlock your device just by reading your finger. It also lets you go past other security screens such as those that require passwords - no need to constantly enter your iTunes password.
One thing that many questioned about Touch ID was how fast it was. It's meant to solve the issue of typing in a passcode every time you unlock the device. CNET have put together a quick one minute video that shows off Touch ID and thankfully it is very quick, nearly instant.