Just ran across what looks to be a cool perl project: MisterHouse.
MisterHouse is an open source home automation program. It's fun, it's free, and it's entirely geeky. Written in Perl, it fires events based on time, web, socket, voice, and serial data. It currently runs on Windows 95/98/NT/2k/XP and on most Unix based platforms, including Linux and Mac OSX.