Almost ashamed to ask but ...

[Krister Ekstrom]

Hey folks,
Krister here with another little query for you.
I'm trying to play an .mp3 file by selecting it on the Gnome desktop and
then hitting the enter key. But instead of nice music, a dialog comes up
saying that Totem can't play this type of file since i don't have a
decoder for .mp3 installed and my question is what package i should
install? I've searched for mp3 decoders, but with no luck at all,
probably because i don't know the propper name of the package, so could
anyone please shed some light on this?
TIA
-- 
/Krister