Apple has released a minor point upgrade to iOS. A very minor point upgrade, given it only fixes two things, although if you're an iPhone user, you should care about at least one of them.
The big news in the rather small iOS 6.1.3 upgrade is that it fixes the bug that allowed easy bypass of the lock screen on the iPhone with a simple set of commands. Or in other words, you should update your iPhone ASAP. For other iOS devices, the only other change is improvements to the iOS Maps for Japan, which is arguably a little less vital for Australian users. Installation can be prompted from the Settings App under General>Software Update.