I've really been using CrashPlan (www.crashplan.com) for backup. I've
got CrashPlan Plus on my main computers (wifes MacBook and my MacBook
Pro) and a Windows PC with lots of internal storage. The Macs backup
to the Windows PC and to CrashPlan Centeral.

I've played with the Linux CrashPlan client a bit in hopes of
switching out the Windows PC as the "backup server" but ran out of
time. My first impression was that it seemed aimed more at Linux
Desktop/GUI users rather than Linux CLI users.

The free version of CrashPlan will let you backup to an external hard
drive as well as other computers running CrashPlan. So for free you
can backup to your friends computer over the internet. While I have
upgraded to CrashPlan Plus and subscribed to the CrashPlan Centeral
service, I've setup my family with the free version of CrashPlan and I
have them backup to my Windows PC over the internet. Works great, even
for my Dad who just uses a Verision Wireless Brodband card for his
Internet access. To make sure he didn't go over Version's 5 GB cap we
backed up his computer to a USB hard drive, and then I moved the
backup files from the USB drive to my backup machine. Worked great and
now the CrashPlan client only has to send updates to the remote
backup.

Another nice "feature" is that Code 42 Software (CrashPlan's
Developers) are based in Minnesota.
http://b3.crashplan.com/consumer/about.html

-- 
Andrew S. Zbikowski | http://andy.zibnet.us
IT Outhouse Blog Thing | http://www.itouthouse.com