The ultimate security for a computer is removing physical access and leaving it disconnected from a network. Your PC is now a glorified metal box but it’s totally secure! Obviously, this isn’t very practical so some concession will need to be made. Assuming we require network access, physical access to the device can be controlled or otherwise limited. But even this is not typically possible in most situations. Therefor, we look to locking access to the computer through the operating system. This is generally an acceptable compromise between security, practicality, and usability.
The typical method of locking a computer is an auto-engagement method based on access – if you haven’t used the PC in x minutes the screensaver comes on and the PC gets locked. Pretty simple but the process but not overly flexible. If you get up and leave the PC unattended there is amble time for another person to sit down and access everything before the auto-lock triggers. The obvious solution is to engage the lock yourself but for most, it’s easily forgettable. Another solution is to have the PC lock itself faster, perhaps after 2 minutes of inactivity. The logical drawback to this is a PC locking every time you get distracted by something like a phone call.
A more clever option is utilizing bluetooth technology, built into just about every cell phone and found more and more often in your PC. A bluetooth device is first paired with a PC; then, when the device leaves the proximity of the PC the computer is locked. That sounds pretty eloquent and intelligent to me. The functionality is provided by a free application called Bluetooth Proximity Lock Utility or BtProx.
Once installed, BtProx can be configured to initiate any command the user wishes once the device has left the range of the PC. It can be as simple as locking the PC or something a bit more involved – perhaps unmounting your encrypted TrueCrypt drive. If you’ve got the hardware requirements the possibilities with BtProx are limitless. I’d be interested in hearing what others are using this software for in the comments!