Well, technically ipod shows to windows as mass storage, so can copy from it all files. Tricky part is how to get itunes recognize them since their names would be just hex sequence...
Software wise: I'd give a shot to
DoubleTwist
Actually not Tricky at all.
use the iPod as mass storage (make sure "Show Hidden Files" is checked in windows.
Create a new folder in My Music called iPod1 or something like that.
Navigate through the ipod until you find folders called F0 F1 F2 F3 etc.... they contain all the songs but scattered throughout those files with no names.
drag them all to the iPod1 folder you created.
NOW here's the cool part, because iTunes created that files structure (or maybe becuase they're tagged, I'm not sure) iTunes can tell what they are.
Just add those folders to iTunes and you're done.
you will losa all structure management etc that you (he) were (was) using but you'll have the music.
