There are a variety of ways to convert an iPod from Windows to Mac, depending on how much metadata (such as playlists, album art, ratings, and date added) you want moved, and how your Windows iTunes library is configured. To transfer with CDs or DVDs, use iTunes Backup. To transfer a lot of music quickly (but not the metadata) try this technique from Cnet.com. Or, to use the iPod itself as a transfer hard drive, with these instructions from Apple.
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ipod to mac says
I have a good ipod transfer software
http://www.ipod-transfer.org/