[any ANONYMOUS forum user]

sudo add-apt-repository ppa:lucid-bleed/ppa
sudo aptitude update
sudo aptitude install rtmpdump

[Stream Recorder]

In Ubuntu 10.10 Maverick you can install rtmpdump (http://all-streaming-media.com/record-video-stream/rtmpdump-freeware-console-RTMP-downloading-application.htm) (rtmpsuck, rtmpsrv) without adding the above mentioned repository. Just run the following in the Terminal:
sudo apt-get install rtmpdump