On a recent episode (#51) of The Linux Action Show (a weekly podcast about Linux), one of the hosts (Chris) was responding to a listener question about editing ID3 tags (that's the metadata attached to media files, like MP3 and OGG files).
This is interesting to me, because I've had sort of mixed results in editing ID3 tags (I've yammered about this before). I've tried the ID3-editing feature in gtkpod, but it consistently crashes gtkpod (ick). So I've been using the command-line utilities from id3lib. That works, but it's a command-line interface, and it's typically a file-at-a-time kind of thing.
Chris suggested easytag, and it's really cool. It's a graphical interface, and it makes it easy to edit the ID3 tags of multiple media files. There are RPMs for CentOS (v4 and v5) on the extras site. Good stuff. Thanks, Chris.