From Ingest a Gazelle:
Turns any USB Flash Drive into a key that prevents unauthorized people from using your computer. Once the software is installed & run, only users in possession of this key can access the computer. If more than one key is needed, additional keys can be easily created. No need to lock & unlock your workstation manually or remember passwords. Simply take your USB drive with you and the PC locks itself. When you return, re-insert the USB drive and the PC will automatically unlock. Great for users with front USB ports that need a secure workstation environment.