Open .rm files in Real Player, not totem in Firefox 3 beta 5

Install Real Player from here
Inside Firefox, Tools, Add-ons, Get Add-ons, mediaplayerconnectivity (or click here
for .rm/Real Media files, you'll want to point to the path to realplayer that you installed.

Depending on your settings, you might have to click *again* the link in the black sidebar.