Or you can just download YamiPod from http://www.yamipod.com.

Simply disable itunes by killing the processes, open yamipod, connect your ipod, select the music you want to restore, and choose "Copy to" from the song menu at the top.

It will ask you to specify the location and "how" the song is saved and your done. Put them where you like, then reboot your computer to start itunes again, and simply add the folders or files to your itunes library using the itunes menu.

Just note, this will not change the copy-right protections on any files that have them.