mpegToaster is a high performance mpeg audio player; from what users tell, it's by far the fastest player on Mac OS X.
If you have an mpeg player running while you do real work, this is the application you need.
mpegToaster uses very little processor time and memory; a highly optimized version of mpg123 is used to decode mpeg audio data and playing is done through the CoreAudio interface, which has minimal overhead.
What's new in mpegToaster
Version 2.0b1 adds the following:
Revamped user interface; most of the new design work for 2.0 was done by Joar Sjöström.
Support for iTunes' music library.
AltiVec detection is now done at runtime, so there is no need for a separate version.