How about Jungledisk
While its a shame it only seems to have a US base which can make uploads slow, it does provide us with a fairly effective offsite backup that we find more convenient and reliable than taking home some kind of rolling incremental tape/drive backup.
When I have looked at alternatives they are usually very expensive, to the point where you might as well just go back to taking a disk home, running Owncloud or perhaps rsyncing to a NAS/HP Miniserver at a remote location.
I would love The Reg to do a summary review of this kind of service at some point or perhaps suggestions in here folks? Brownie points for services that don't require you to generate and debug scripts to get it all setup and aren't soley tied to MS Server OS' AD or any of that other bling.