Wake on LAN is intended to turn on machines through it's LAN adapter, for example if you need to deploy some software at night and users left their machines turned off, you can use Wake on LAN to turn them on and start the software deploy.
There are many tools for it, one I've found useful is wolcmd, an executable that allows you to turn on your Wake on LAN enabled computer, from a command line. You can download it from depicus. They also have more tools similar to it.
Just like repeatedly turn it on and off! Fun for hours.
Typical use - I share an internet connection. The modem is on my SO's PC. There's often too much cra... - err, junk - in her office so instead of risking breaking my neck to go in and turn her PC on I've set it up to wake on LAN.