Simple Hack to Add Free Custom Ringtones to your iPhone - iPhone Hacks

Cool find. Simple, super-fast way to add custom ringtones to your iPhone.

http://www.iphonehacks.com/2008/08/ringtone-hack.html

Have fun.
Sarah

PS> There's only one instruction missing: Go back to your original song in iTunes and reset the Stop time back to it's original setting.

I discovered this the other day when listening to a playlist with one of my "ringtones" and the song only played for 30 seconds.