I've currently got a usb mic plugged into a Raspberry Pi B+ and am using the following code to record data: arecord --buffer-time=5000000 -D plughw:1,0 -f cd -t raw | lame  -r - stream.mp3I then serve the resulting stream.mp3 file on the pi using Python simplehttp and listen to the recorded data using mplayer on the command line. I'd really like to skip the step of saving audio data on the pi if it can be helped. I've tried various attempts at piping the audio data using ssh and netcat to mplayer on my mac but have not figured how to do this. It's not important to me to encode the audio using lame; I'm simply doing that to save space and bandwidth. 
Saving from arecord on a raspberry pi across a network to a mac
ssh;command line;pipe;netcat