bsplayer can be used with no codec installation, with just the decoder files copied to the CD and a correct bspfilter.dat file (rename bspfilter.sam to bspfilter.dat)
I have never tried it myself, but here are a few links that may help you:
http://forum.bsplayer.org/viewtopic.php?t=1152
well okay, there's only one in fact...