Mp3 player firmware replacement, RockBox, now plays NSF, SID, and SPC files
RockBox is a community driven firmware replacement for several popular mp3 players (iRiver h1x0/h3x0, Cowon iAudio X5/M5, Apple iPod 4th gen). The current version plays NSF/NSFe, SID, and SPC files. Chip tunes on the go without having to convert them to ogg (or mp3) first. All my tests of nsf and spc files seem to been without error, and they played at full speed.
source : VORC