Found on Schockwellenreiter, looked at and immediately dismissed as nonsense: Substance Softwares Phew. Reason:
NOTE: Phew currently doesn't backup the resource portion of files. In short you may find incomplete files on your backups (text clippings for example). This probably won't effect 99% of most peoples data but please check critical files after a backup to make sure.
This doesn't just affect rare files. All applications that use the Carbon API and don't come in bundles or need to store in bundles require the Resource Fork. With this backup software, you can't even back up a whole range of Carbon applications, as their Resource Fork is lost - and that's where the entire program code is stored.
Sorry, folks, but until this problem is fixed, it doesn't make sense to use it. I'll stick with psync and psyncX, which may have a rather primitive interface, but at least a backup to an external drive is not only complete, but even fully bootable. And they're not only free, but also open source.