AtomicParsley is a command line program for reading, parsing and setting iTunes-style metadata in m4a files (really any mpeg4 file container: m4b, m4p, m4v, mp4).
Browse your iTunes Collection by Cover (OpenGL Animation)
aus dem bei O'Reilly erschienenen 'iPod + iTunes'-Buch
This is a wrap-up on how to create a proper podcast feed on Drupal 5.7 (will probably work on 6.2 as well), based on a particular content type, valid for the iTunes Music Store and redirected via Feedburner.
iPodFS is FUSE based filesystem allows you to mount the iTunes DB from your iPod and use it like others USB-connected music players, which interface with the computer like a hard drive. It lets you access the files on the iPod from the command line and play them by your favourite MP3 player.