I had played with WOL (Wake-On-LAN) some years ago but now with the way tablets are spreading and being able to RDP from them to any computer this old school trick makes it too easy to turn your computer on from anywhere and be able to log into it remotely (for those little things that your mobile browser just can’t do yet).
I want o give a shout out to Mathew who’s post had me up and running in Win7 in less than 5 minutes.
PS: try the WOL Sniffer, it works like a charm.