My favorite remote backup tool for Mac or Windows is JundleDisk.com - highly secure, highly automatic, and very affordable. The service backs an encrypted copy of your data on Amazon S3 servers for about $0.15 per GB. I have FileVault enabled on my local machine and regularily perform a local backup of my data. But a remote backup is also essential.... Mozy.com is also a similar service but I have heard some mixed reviews. Carbonite.com is coming out with a Mac client soon as well....