officially, apple does not support this, however there are several 3rd party methods for accomplishing your goal.
some shareware solutions:
OSX
http://www.apple.com/downloads/macosx/ipod_itunes/musicrescue.htmlwindows
http://codershole.com/idump.phpthe easiest way, depending which ipod you have and how it is formatted, is just to explore the hidden ipod_control folder with windows explorer or via terminal in OSX.
since you didnt mention which type of computer you have ill discuss both.
in windows, connect your ipod and open windows explorer, either by pressing the windows key + e or opening my computer from the desktop.
select the drive letter for your ipod, usually e, f, or g.
in the location bar near the top of the window youll see it change to e:\ or f:\ or whichever drive letter the ipod is using. click there and type ipod_control. it should now read e:\ipod_control\music (assuming e is the drive letter). press enter.
you will now see many folders beginning with F followed by two digits. these folders contain your music. copy them to your hard drive and/or import them into itunes directly.
the process is somewhat more complicated on a mac.
first, connect your ipod.
then open the terminal application. create a new finder window, click on applications, click on utilities, and then double click on terminal.
type "cd /Volumes/the_name_of_your_
ipod/iPod_
control/Mu
sic" without the quotes. note that the capitalizations are important in this case, and that you should type the name of your ipod instead of the_name_of_your_ipod. if it has a space or any characters besides letters and numbers, like * or ' or $, you will need to put a \ in front of each of those characters. so if it was "joe's iPod" you would need to type "joe\'s\ iPod"
assuming this has worked, if you type "ls" without the quotes and press enter you should see the same folders as in the other method, F00, F01, etc.
type "mkdir ~/Desktop/savedmusic" and press enter
type "cp -rv* ~/Desktop/savedmusc" and press enter
it will take a few minutes, to run, but once the screen stops scrolling, your music should be in a folder on your desktop called saved music and ready to import into itunes.
in both cases, windows and mac, the file names will not be nice like "Cake - Italian Leather Sofa.mp3" but more like "QEWUIHRIO.mp3". Don't worry, once you import them into itunes, it will be able to read the correct information out of the file if it was stored that way in the first place.