The Raspberry Pi is an ARM/Linux powered Mini-Computer for just $25. It plugs into your TV and a keyboard. This capable little PC can be used for many of the things that your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. And last but not least it is a great system for webhosting/web development.
The Raspberry Pi can be ordered from the Raspberry Foundation at http://www.raspberrypi.org/faqs.