Ensure Technologies makes small devices that transmit encrypted wireless signals to a PC, without which the computer will turn off its monitor, keyboard, and mouse. The company has just signed an agreement with a watchmaking company that will build that proximity signal device into a wristwatch. The watches will use a unique 32-bit security code, programmed by the user, transmitted at low power in the 900-MHz frequency band. The company is developing additional uses for the system including security for PDAs and mobile phones.

To read the source article, go to pcworld.com.