how do you change helper apps in Kde apps

[marko]

For example I'm using konqueror and when I select a
shoutcast radio station, it wants to open it in amarok
but I want it to open in rhythmbox. How can I
change listen.pls links to run in rhythmbox
instead of amarok? Similarly, if I click a multimedia
file like a mpeg file in Kmail, it wants to open it
in mplayer but I'd prefer vlc. I'm thinking there's
a global setup tools somewhere in KDE but just don't
know where.

Mark