Is anybody using S3 for backup from a Linux server?

If so, how are you doing it? Right now, I've got a cPanel server that I'm backing up to S3 via infiniteftp, using bmu. It backs up a couple of accounts per night, tars and gzip's them and ftp's them to infiniteftp. From there infiniteftp puts them into my S3 account.

I've looked at just mounting S3 directly, with elasticdrive or something similar, then using rsync to keep my whole /home directory tree updated on S3 but it seems like doing it this way would be more expensive as there's a whole load of PUTs involved.

I'm just wondering how other people are doing this...?