just a kwick n dirty note:
for linux users it is sometimes not funny that just one application can write/read from /dev/dsp.
but there's a solution for this:
I) first, you need to have alsa-sound working,
II) then install the realtime soundserver called [jackd],
(for debian users: sudo apt-get install jackd) start it: jackd -d alsa -d hw:0
now you can use different applications with jackd, there's for example a plugin for xmms xmms-jack - xmms output plugin to the jack audio server, to switch xmms to using jackd instead of alsa or the oss sound system. programs like mplayer allready have support for jackd. There is a lot of Applications that are [ready to run] with jackd.
III) if you want to run other apps, without jackd-support and you want them to use jackd, you can start another soundserver artsd (it comes with KDE, and in my case i just had to restart the sound-system and did just a klick in KDE's controll-center, jackd support was allready built in (i am using debian unstable), for sure there are many other ways doing this on the commandline, but for now i talk just kwick and dirty...
if artsd is running with jack, you can simply start your app, like skype or even teamspeak with this command:
artsdsp -m <appname>
see also [[1]]