the latest version of ps2mp3 is avaible there:
this is a ps2mp3 binary with some changes from the original ps2mp3.
1-it supports volume changing (50 volume level from 0 to 3FFF)
2-it's recompiled following pixel's suggestion and now it works from some hdd utils like ps2os ps2menu ect
3-sorry english guy but i translated it to italian maybe i'll restore the english text when i have time.
here you are the changed source and the binary