This is one innovative product released by Thanko Japan, that deters people from using your USB devices, usually a USB flash drive.

USB padlock

Basically the USB lock is a combination lock that fits on the standard USB male connector port, and nothing but the correct combination allows access to the USB device.

I doubt the padlock would actually deter real thieves from getting to your important data or USB devices, but it will definitely act as a strong notice to annoying friends and colleagues who constantly borrow things without asking.

Product page via akihabaranews