Originally posted by: Evander
I think audacity will let you trim only if you reencode the audio (could be wrong though)
In any case, there's a freeware tool that specializes in this, I use and recommend it myself: Mp3directcut
http://www.mpesch3.de/
It trims mp3 files withou reencoding (it can fade in/out also). Here's how to use: go to the start of where you want to cut and press "set begin". go to the end of what you wanna cut and press "set end". a region should not be highlighted. just press "cut", then save the file and you're done