If you use a key to block access to your home or your car, why not do the same for the computer?
Predator turns any USB memory device into a key that blocks access to your computer. How does it work? Predator creates a special key in your USB drive, and then sits in the system tray while monitoring it. The key is renewed every few seconds for more effective protection.
The moment you leave your computer, simply unplug the USB memory device and your computer will be blocked: the screen will go black, and the keyboard and mouse won't respond. When you're back, plug the USB device again and Predator will make your PC go back to normal.
Predator is easy to use, though it could benefit from a bit more information about the program's functions and a proper help section.
With Predator you can block access to your computer while you're away with a simple USB memory device.