If you use Linux and have a professor that uses iTunes U to post lectures and distribute content, you may be frustrated that you are left out in the cold (assuming you don't have a Windows or Linux machine lying around anywhere).
Fear not! I came across an app called TunesViewer this morning, and it works really well. It lets you search iTunes U and iTunes Podcasts, and then download the content. More information, as well as downloads, can be found here. There are .deb, .rpm , and .apk (Android) files, so it should work no matter which distribution you're running.
Check out a quick screencast (no audio, sorry) of it running in elementary OS Luna:
[youtube=http://www.youtube.com/watch?v=5TKlluClfhs&w=640&h=360]