Here's an alternative suggestion: If you have WINE installed on your system you may want to take a look at mptrim (formerly called mp3trim). It is the easiest way I've found to trim the silence from the start and end of an MP3 file, and it will also normalize the volume if you desire, so all your MP3's play at the same volume level. The only downside is that the free version will only handle MP3's up to around 7 minutes in length (it actually counts frames so this can vary), but you can always use Audacity on those long ones, it's just a bit more labor-intensive process. Mptrim is a Windows-only program, but the older version I have (MP3Trim) runs fine in WINE, so I assume the current version would also.