Sopcast Player

sudo add-apt-repository ppa:ferramroberto/sopcast
sudo apt-get update
sudo apt-get install sopcast-player

Associate sop:// links with Sopcast Player using the commands below:

gconftool-2 -t string -s /desktop/gnome/url-handlers/sop/command "/usr/bin/sopcast-player %s"
gconftool-2 --set --type=bool /desktop/gnome/url-handlers/sop/enabled true
gconftool-2 --set --type=bool /desktop/gnome/url-handlers/sop/need-terminal false 

*For Ubuntu 10.4, 10.10, 11.4