For Linux-challenged (and empy-100GB-disk-deprived) users (who thus cannot use mirrordir or simply FTP everything in one gulp), if they want to avoid a simple exercise of writing a script that would FTP fid files one by one, I recommend recently mentioned
Lazy Bastard's Guide to Cloning your empeg by Roger. It might look intimidating for penguin-phobes, but it is dead-simple to follow literally even if one doesn't understand a single command (and those who do think "why didn't I think of this").
Clone tool and Jemplode are still only point-and-click solutions, but Roger's solution is so elegant and fast (it transfers directly empeg-to-empeg, cutting total traffic in half and avoiding emplode protocol overhead) that I still prefer it over them.
The guide does not cover cloning of partition containing EQ settings, play counts etc.
I think this should be FAQed (don't blast me too hard if it already is, FAQ gets improved faster that I can follow

)