xmms works for me.
I add Dag Wieers rpmforge repository with:
rpm -Uhv http://apt.sw.be/packages/rpmforge-release/rpmforge-release-0.3.6-1.el5.rf.i386.rpm
Then:
yum install xmms xmms-skins xmms-mp3
There was a problem in that the doublesize option didn’t work correctly but this has been fixed with the latest update (1:1.2.10-14.el5.rf).
To enable mp3 in totem and rhythmbox (and for Sound Juicer CD ripping to mp3) you can do:
yum -y install gstreamer-plugins-bad
yum -y install gstreamer-plugins-ugly
These also come from rpmforge.

btw: the binary for kernel module file also available at http://namran.net/repository/xlinux
I wish it were so easy… no matter what I do, I get an immediate reboot when launching a custom kernel. No idea why.