[darius]

Man, good idea... unfortunately I didn't even think about personal use for S3 and I already signed up for an online backup service. I kept thinking that an online backup system would work great with S3 but not for a second I thought of using it for myself :(

[cperciva]

There are some tools available for doing backups directly to S3; but they all have limitations because of S3's rather weak API. In addition, the pricing structure of S3 (bandwidth + storage + a significant per-request fee) means that certain workarounds (e.g., adding indirection) end up being absurdly expensive.

S3 can be an excellent backing store for an online backup service, but only if there's some intelligence sitting in between client systems and S3.