I used Panther's Fast User Switching feature and three user accounts:
- The first account was the playback account, where the music originated. I set up Nicecast to stream iTunes' output to port 8000 (the default). I then started a playlist playing.
- The second account handled streaming to the AX in my family room. I opened iTunes, selected my family room speakers, selected "Advanced>Open Stream...", and typed in "http://localhost:8000". The music started playing on my family room stereo.
- The third account handled streaming to the AX in my study. I followed the same steps as the second account except that I selected the speakers in my study. The music started playing there too!

