Isn't this going to be very slow ?

I would assume so, but I just tested the software with few files. Soon I'll be using it on the empeg for a full backup first, and a sync later with just few extra files to be downloaded. I don't think it's going to be a mojor problem since I don't plan to backup more often than when I put new files on the empeg, which does not happen frequently. However, Mark makes me think of a suggestion for Hijack, if it is possible/convenient:

what about a rsync server in hijack, startable when needed from a new hijack menu item? Too much mem?

Just thinking about how to refine the idea: what if we
1) installed the necessary files in any dir on drive0, as Roger recommends (maybe we could create a distributable zip with the files ready to go, so that it is more user-friendly to those who are not failiar with linux)
2) configure config.ini with the proper path to the files
3) Have a hijack menu item that starts/stops the rsync server (from the above mentioned path?)

?

As usual, not an expert in linux, sorry if this does not make sense