Easy Remote Backups

My recent experience with dodgy computing has meant that I've been kicked to look at backups again. Fortunately I've had no data loss (I think) - so it's just a matter of 'putting everything back'. I've got a new external hard drive (with more than the capacity of my two existing ones put together) - I'll be using these from time to time, but storing them elsewhere. I've also signed up for a Mozy account which'll back up photos, music and key files. (Nb - using that link gives you 10% off). The photos are irreplaceable (flickr isn't backup) - and the music is just a convenience (how long to convert those CDs?) - The backup will take ages initially, but is then offsite.

However, the speed and immediateness of a hard drive backup is also a big advantage.

Backups also need to be automatic, or they get forgotten - Mozy has a big advantage here (I've not found a good way to do this with local hard drives). I did have 'retrospect', but it tended to slow things right down just when I needed the computer not to slow down - and it's just so easy to say 'later'. Suggestions for decent backup software are welcome.

I'll tell you, the backup thing alone makes me consider OSX with 'time machine' and 'super duper'.

I started thinking, is there some way to combine the convenience of hard drive backup, with the robustness against fire and theft of off-site?

In other words: Is there a hard drive solution on the market which does the following - I can plug it into my network, and copy files to it quickly. I'd want them encrypted. I'd give the box to a trusted friend, who would plug it into their network. The software would then do differential backups over the net (with a secure tunnel).

The quid-pro-quo is that I'd have my friend's backup box on my network. The two boxes are connected so that either person can request max and min bandwidth, the actual bandwidth needed would be a compromise between those requests.

I know that such a thing is possible (though I've not found out how) using rsync, mcrypt and all that, but these tend to rely on a 'nix setup. This box would be 'consumer friendly', self contained, and an ftp-like bit of software on the computer to be backed up which'd select and send the files, and deal with the technicalities of managing the connection (i.e. on the phone with friend, you'd both run the software and it'd email the connect info for your hosted box to the other person). It'd would work for winxp, OSX... whatever. My computer would talk to my box (in his house) and vice-versa.

The files are encrypted to remove snooping temptation from the host.

I could grab files back at any point - or for a big recovery I could just go get the hard drive. As the box is plugged into the network, it would not require my friend to have their computer on whilst I backed up, only their router.

Does such a thing exist? (I guess not)... is there a way I can get close using clever scripts?

If you make hard drives, and and think this'd be a great product, can I have one... or rather, two?