In a nutshell, the reasons I like JungleDisk are:
- Native clients for Mac, Windows, Linux. I'm currently backing up a mix of XP, Vista and Mac OSX systems with one consistent backup solution.
- Simple configuration of scheduled backups.
- Easy access to files from other computers via the local JungleDisk.
- My data is encrypted locally, transferred securely via HTTPS and stored in encrypted format on Amazon's server.
- The automatic backups keep (by default) a 30 day revision history.
- The cost of the software is only $20 for all computers (plus S3 storage fees).
I also have automated backups set up to back up the local user folders on each computer to the S3 datastore. Most update daily, but for C's work computer, I have it update hourly. Her connectivity when working on work files tends to be spotty, so this strategy tries to make a backup more often to sync up her document edits as soon as possible after connectivity is restored.
Once copied to the backup "bucket", the backed up files are available to any other computer (4 others in our case) that also has JungleDisk installed. There is an additional feature available for only $1 per month that allows web access to the JungleDisk data as well, so a local installation of JD is not needed. That's not something I need right now, as I can use my webhosting service (unlimited storage space for $7/mo) for keeping handy access to files I might want to access via a browser only.
So, bottom line - JungleDisk rocks, Amazon S3 is affordable, and the system just works to provide simple automated offsite backups for multiple computers.