AtomicParsley
AtomicParsley let's you tag MPEG-4 files such that when you bring them into iTunes, all the tags are there, including marking the song as a "Music Video". This is great cuz otherwise you'd have to re-type in all the tags and manually set the song to "Music Video" in order to get it to show up that way on your iPod. Well yay!
The only problem was that the current binary is 2 years old, and did not include support for iPod or iPhone MPEG-4 files. I've modified the source by applying the correct patches. To comply with the GPL I have provided the source code here. If you wish to make your own modifications, you can download this and compile (make) it, and then place it in the /Library/Application Support/kJams/ folder.