mp3Trim is a simple and easy to use MP3 editor. Its main advantage is that it works directly in the MP3 format without having to decode/re-encode, so it is very fast and doesn't degrade the music quality. mp3Trim can trim the parts that you want to discard. mp3Trim can adjust the volume - either manually or automatically (normalization) - for example, to amplify those pesky MP3s that were encoded too low. mp3Trim can fade-in/out abrupt beginning/ending. mp3Trim can clean up your MP3s and recover wasted disk space.
News source: MP3Trim Home Page
Download: mp3Trim 1.78 Beta 1
This is BETA software!, please use caution when installing it on your system