We posted yesterday on the MacRumors tutorial on creating ringtones from your own music by changing the file extension. Well the guys over at applegazette have put together iRing a simple Automator application that, well, automates the process. Pretty much all it does is take the AAC file, change the extension, and put it into iTunes. Apparently iTunes has to be closed for it to work properly, but if you don't want to go through the rigamarole by hand, this might be handy.
iRing is a free download from applegazette.
Update: Alas, events have overtaken this post (which was written the night before). The iTunes 7.4.1 update breaks the very vulnerability this uses. It's against our policy to remove posts, but we should note that this will only work with iTunes 7.4.
Update 2: Apparently the guys over at applegazette have updated iRing so that it works again with 7.4.1 (see the comment below)