playing and ripping, ogg and mp3s?

[Tony]

I have tried playing my ogg files with XMMS on my ubuntu installation,
but it does not appear to work.  I have been able to install Real
Player and it works O.K. So I would assume my sound card is not the
issue.  Can someone clearify what software, above the basic ubuntu
installation, is necessary to play ogg and mp3 files?

What about for ripping CD's to ogg using GRIP?

Thanks,
Tony