Unlike other iPod software to copy songs off the iPod, iPod.iTunes does real add-synchronization, even in two directions if desired:
Source
Target
iPod
--->
iTunes
iTunes
--->
iPod
(from iTunes to iPod is especially useful if you want to synchronize from iTunes to an iPod which is linked/synced to another iTunes library)
iPod.iTunes evaluates the source for songs, podcasts, videos and/or playlists that are not in the target and only adds these seamlessly, avoiding duplicates, saving your time. Unlike iTunes' "auto update/sync" function iPod.iTunes generally does not delete content in the target. iPod.iTunes can also transfer song dependend data like "My Rating", "Last Played", "Play Count", album artwork, etc...
8 synchronization modes in 2 directions (from iPod to iTunes and from iTunes to iPod).
Option to choose songs manually if you don't want to synchronize them all. You can listen to songs before you choose to transfer them.
Songs and playlist entries can be synchronized together or separately. If the songs on the iPod are already in the iTunes library and you only want the iPod playlists, you can use the playlist synchronization alone.
More...
What's new in this version:
Compatibility for Mac OS 10.6.2.
An improvement for the "iPod Emergency Copy" function when used with PC-formatted iPods.