Considering on-line backup

Considering S3 for on-line storage/backup, I'm looking around for tools to do that (or competitive non-S3 solutions).

Interesting blogs/places related to the topic:
John Eberly - using s3fs and rsync. Should lead to UNIX-portable solution.

Encrypted offsite backup with EncFS, Amazon S3, and s3cmd - AES encrypted data (via encfs) are synced to S3 using s3cmd.

Non-S3 solutions that seem interesting so far:
Jungledisk - maps S3 bucket as disc, 30 day eval, $20 per license (any computer sharing the same S3 bucket). Crossplatform.
Mozy
2.2 GB free, no transfer cost, Windows only, 5$/month unlimited backup.
Block-level upload/diff. No versioning, no web access in the basic version.
Carbonite - 15-day trial. $50/year (e.g. $4.2/month). Windows only client, Mac Beta. No versioning.
DropBox - versioned cached network folder, 2 GB free, 50 GB $10/month or $100/year. Crossplatform clients + web interface. Data are stored both locally and on the server, multiple machines are synchronized.

More general S3-based tools (crossplatform/UNIX):
s3fs - S3 plugin for FUSE, there is a commercial version on subcloud
s3cmd - command line scriptable application for copy/get/make bucket against s3 (GPL)
Js3stream - Java app usable as filter to store/retrieve a stream to/from s3.
s3browser - Windows NET 2.0 freeware GUI for S3 bucket management
Jets3t - Java toolkit for S3. Did not test.
Sync2S3 - Windows based sort-of-rsync (?) tool. 30 USD per license.
S3 Firefox Organizer extension- Firefox extension in a commander-like style. What about encryption?

Tools to get S3 as Windows drive:
s3drive - freeware, proprietary, NET 2.0