If you want an easy way to control your Mac from wherever, there's an app for that. http://www.themacbox.co.uk/tweetmymac/ You can get your external IP (useful for remote access apps), sleep, let your mac speak, take screenshots and iSight pics, open apps and even download torrents from any Twitter interface or client. You can also let people who you trust to control your Mac follow that Twitter account and make commands on your behalf. For PC users, there's also TweetMyPC
