Pcutmp3
From TMB Wiki
Pcutmp3 is a Java based program that lets you cut and trim MP3 files losslessly (i.e. without any quality loss as there is no re-encoding). Ideal for removing adverts or unwanted intros/outros from your radio mixes.
Download
http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=35654&view=findpost&p=314305