[Negrito]

It may not be the ideal solution for those in need of some military-grade security, but those simply looking to keep their co-workers from snooping on their laptop may want to consider Phoenix's new Freeze application, which promises to turn any old Bluetooth-enabled cellphone into a proximity lock. What's more, you can apparently even use one phone to control multiple laptops, and configure the application to switch the laptop into a power-saving mode when the phone moves outside the proximity zone (which can also be configured to suit your needs). Best of all, the application is available as a free download right now (Windows XP and Vista only, unfortunately), and Phoenix seems to have some even grander plans for the future, with it now apparently busily courting computer manufactures in the hope of getting it offered as a standard option on new laptops.

http://www.engadget.com/2009/05/06/p...roximity-lock/

http://www.phoenixfreeze.com/