[CentOS] sound

I am using Cent OS 4.6 and a USB speaker (no sound card but USB speaker
works fine).  Problem is, if I use something like xine or realplay and then
later want to visit youtube through firefox, the youtube sound won't
work, because even though I exited xine or realplay somehow it still has
control of the sound device.  Someone in fedora list suggested pulse audio
but I can't get that installed.

Any suggestions?  I don't want to have to reboot my machine all the time.