GreenITStrategy.com

The team at The Manageability Team Blog have posted a very comprehensive article on how to setup Wake on LAN (WoL) capabilities using System Centre Configuration Manager 2007.  WoL enables you do things like implement security patches on PCs that have been sleeping (i.e. saving energy when not being used)...excerpt here:

"Wake-on-LAN (WoL) allows properly configured (BIOS, Operating System, Network Interface Card) machines to resume operation from various sleep modes in response to a network request.  The network request comes in the form of a magic packet which is a special formatted network packet.  Sleep refers to the low power states of Windows XP and Vista: Standby (S3), Hibernate (S4), and hybrid sleep. Hybrid sleep is a feature of Windows Vista that combines the features of S3 and S4; when entering sleep a hibernate file is saved to the hard disk but the computer resumes from memory unless power is lost. This can create problems if systems like Configuration Manager need to distribute software to a collection of hardware devices. An example would be a Security Patch that needs to be implemented as quickly as possible for a set of vulnerable machines. By combining all the pieces to create a WoL ready infrastructure, you'll end up with an environment that allows networked PCs to be both responsive 24x7 and efficient from a power consumption perspective."

Check out the full article here:  http://blogs.technet.com/smsandmom/archive/2008/03/04/configmgr-2007-implementing-wake-on-lan-wol.aspx