Recently I gave a presentation on Plug Computers at the local NCLUG.  Plug computers are inexpensive, small, and low power computers, about the size of a wall wart.

They make great home servers, appropriate for file sharing, exporting media files for your devices (DLNA), making backups (backuppc), etc.

If you would like to check out the slides for my presentation: Plug Computers Presentation

If you would like to see my wiki notes on plug computers: http://wiki.xkyle.com/Plugcomputers