How do I output my audio input?

A few iterations ago, I think this was Jaunty but could've been before, I would plug a 1/8" audio cable from the line-out of a Windows netbook to the line-in of my Ubuntu machine, so I would have all the sound from both machines without having to plug both into a mixer which I don't have. I didn't do this much, as I was pretty-much happy with Banshee at the time. But with Karmic, and still with Lucid, I can only get the output if I'm recording with Audacity. Which I'm not going to do from my web-development and systems programming workstation.

I can tell by plugging in headphones that my netbook has audio out working. I can see Sound Preferences that the Ubuntu machine is receiving them. I just want the old behavior back. Help?

From ubuntu VarLogRant

• If I understand correctly, you're trying to stream the microphone input to the audio output? The simplest I can think of is to use gst-launch for that. Open a terminal and type:

  gst-launch pulsesrc ! pulsesink
  

  The press CTRL+C to stop streaming. You may have to install the gstreamer tools to have this available:

  sudo apt-get install gstreamer-tools
  

  Note that as I don't have any suitable audio source, I didn't actually try that so it may not work. Any feedback on whether it does would be appreciated.

  Source Lab : It works quite alright..

  VarLogRant : That it does. I got the answer on the weekend and have the problem on my work machine, so I didn't want to say OK until I tested it. And I'm testinb it right now. It does work.
  From Bruno Girin