I can easily run the server side at (say) port 50001 instead and have "something" listen on port 50000 and connect to port 50000 and pass the data back and forth between the two, logging it as it goes, although I don't know what to choose for "something".
Wouldn't the "something" be netcat and tee. I googled and came up with these:
http://smaftoul.wordpress.com/2009/05/13/netcat-as-a-logging-tcp-proxy/ http://blog.hawkhost.com/2009/12/12/using-netcat-as-an-intercepting-proxy/
Hope that helps, Richard