There was a recent article in the Boston Globe about backing up personal computers and it discussed two companies that were in the market.
One of them, Mozy, will backup 2gb of data for free, with an all you can eat plan for $4.95/month.
They also do businesses (define as MS server OSes) and that will cost you more. No they don't do Linux, but they do do OS X 10.4 and above.

In the interest of full discloser, yes I used to work for EMC, but no I am not pimping this so Moshe can buy a new helicopter.