Puddletag is an awesome mp3tag-like audio tag editor for Linux about which we've talked about last week.
Puddletag comes with Ubuntu .deb files but it doesn't have a PPA for easy updates so thanks Mrbig2000 and RobJN's suggestion, I've created a PPA.
Add the Puddletag Ubuntu PPA and install Puddletag in Ubuntu Lucid, Maverick and Natty (tested in Maverick only!) using the following commands:
sudo add-apt-repository ppa:webupd8team/puddletag
sudo apt-get update
sudo apt-get install puddletag