As of 2009/03, Insteon is fully supported for open source on unix or windows, but for this you must use a P(ower)L(ine)M(odem) (not a serial or USB PLC) and use it with misterhouse.
A favorite site of mine is Linux Home Automation. Decent amounts of good information.
I am of the opinion that Home Automation isn't as far along as it should be.
Etch the 1s and 0s into a steel plate. Then seal it in one of those food vacuum seal bags. Then put that bag in another bag.
That should do it. It'll last forever, and can be manually recovered easily.
Side note:
This was on the bottom of the page: " There's nothing like a girl with a plunging neckline to keep a man on his toes. "
Our informal mission is to improve the love life of operators worldwide. -- Peter Behrendt, president of Exabyte