Out of the box, your Mac is a relatively secure piece of equipment. It comes with a firewall, is more-or-less immune to viruses, and can be locked in a number of different ways. Airlock is a new piece of software that aims to add an extra level of security, in conjunction with an iPhone or iPod touch.
Whenever your phone moves a certain distance away from your computer, Airlock can automatically lock the screen. When you return, your Mac unlocks automatically. It’s a very simple idea, but one that could prove useful in many different circumstances.