What does the Wake-On LAN cord do? What is it for? WTF SHIZZLE!
A remote wake-up technology that enables you to remotely power systems "on" for off-hours maintenance. A result of the Intel-IBM Advanced Manageability Alliance and part of the Wired for Management Baseline Specification, this technology helps save time on automated software installations, upgrades, disk backups and virus scans. Equally important, it increases end-user productivity by moving such planned disruptions to off-hours.
More info: http://www.webopedia.com/TERM/W/Wake_on_LAN.html