Who is Curtis?
Lemme take a wild stab and guess the bulk of your files are goth metal?
Sure, you can compress an mp3 to ever smaller files. The trade off is audio quality, which is going to get worse and worse. The basic gist is that by going to a smaller file size, you get a lower effective sampling rate, among other things, and the player has to interpolate more--hence worse sound. But, if you want your songs to sound like they are being played through a telephone, get yourself a copy of LAME and process your files changing the settings to lower and lower audio quality.