I send my stuff by ftp to DriveHQ[1] (
www.drivehq.com). I use cron to run the shell script which uses tar to compress the files then sends them by ftp.
DriveHQ give you 1Gb free, so my offsite backup is done automatically and free, result!
I can get at the backup from anywhere with a internet connection. I don't have to worry about security or availability of other computers.
PM me if you want more advice.
[1]no connection, just a happy customer.