Have you found your iPod useful for the study of languages?

Did you have any problems using the iPod to study languages?

Did you use ratings to keep track of how well you know given vocabulary and dialogues? If so, was this helpful?

Did you find the smart playlists (least known, least studied, recently studied) included on your iPod helpful? Did you create your own smart playlists? If so, can you describe what types of smart playlists you created?

Are there any other language study resources that you would have liked to have had on your iPod?