I have worked with http://www.rsync.net/ before. Starting at $1.80/gb/mo. There are other commercial backup services out there, but not many support the mac. You can access webdav servers with the finder natively -- it is the same technology/protocol Apple uses for their .mac idisk.

Here's a link to their Mac OS X page:
http://www.rsync.net/resources/howto...tegration.html

More on the burn to DVDs and leave at a friend's house technique... you could make disk images and encrypt them, or make encrypted disk images... that way you could feel more secure about your data finding its way out without your supervision. You may also want to keep a copy at your desk at work, again encrypted for your privacy. I know others who just keep a copy in the trunk of their car, but I wouldn't depend too heavily on that, since temperatures and constant movement can be detrimental to long term media storage.