Okay its time for another "can someone please just build this" type of request. So lets get a few things straight
1) I know that there are cloud backup solutions out there
2) Yes I know that theoretically you could set up rsync to do this.
Now here is the problem
On my computers I have three basic sets of data
1) Work related information - Needs to be backed up securely and if I lose it then its a pain but anything decent will be in my email archive
2) Personally highlighted information - e.g. my flagged photos, stuff that is irreplaceable
3) Stuff I'd prefer not to lose - e.g. the rest of the photos and videos
Now effectively this could give 3 different backups but instead I'd say that actually its only two sets but they need to work together.
1) a Local disk backup
2) an occasional cloud backup
Now to people who run data centres this is all old hat and is basically the "ship the tapes off" part, but I think we can make it a little smoother. So what do we need?
1) A way to specify what is in the backup
2) A way to specify what is backed-up further into the cloud
3) A way to specify the security applied to the backup files
I'm going to deal with 3 first. Now if you have an encrypted hard-drive or password protected elements then clearly the default on the backup needs to be at least that strong, this presents a bit of an issue as it means you have to be able to decrypt to determine the deltas so in other words an approach which is linked to the security profile of the user makes sense and where its hard-drive encrypted its easier as once you are in you are in.
So now to the other pieces, I won't cover item 1 as that is pretty standard in most backup solutions but I'll go onto the second instead.
What we need is some way of specifying which elements we want sent to the cloud for offsite backup. As an example in iPhoto you might decide the flagged photos need to go to the cloud or you might decide that all photos go. These elements are automatically added to the local disk backup but would then be added, for instance daily, to a cloud backup.
Now the surprise here is why TimeMachine doesn't have this sort of facility in conjunction with MobileMe or another Apple branded cloud provision or why Microsoft's massive spend on the cloud hasn't produced something similar. It really is an obvious idea which is basically that key sections (or all if you have a fast enough connection and cash) should float from your local storage onto the cloud.