More and more churches are evolving from podcast to vodcast (video podcast). If that includes you check out MetaX, it's a really simple and effect FREE meta-data tagger for mp4 files and their derivatives like m4a audio files.
Basically after you've edited your video and your ready to upload, you just drag and drop your file on MetaX and the above dialog box opens. You can change the tittle, the artist, the genre and just about any other category you can think of. You can even add a copy write, episode url, keywords, a brief description and cover art to give your vodcast a nice polished look.
And the best part is when your done adding and editing the meta-data, you just click the write button and you'll hear a cow moo when MetaX is finished.
It's only for mac but they did just updated to Leopard. So if your a windows user you could try Jaikoz . The downside is it's $30.00 and probably more powerful then what you really need.