Misu is a new iPod music transfer utility for Macs that makes it easy to transfer music between two iPods.
Simply select the source and the destination and let Misu go to work. It then compares the two iPods, figures out what’s missing, and syncs them together.
Currently it’s only in super-secret private beta mode, but courtesy of TUAW, the super-secret code that you’ll need to get a copy is 48372.
Plus, if you try out Misu during the beta phase, they’ll give you a free and licensed copy of the final version as a thank you. (This code is only good for today, but if you miss out, you can still get a free copy of Misu by becoming a fan of the Misu Facebook Page by the end of March.)