This is an awesome tool.  It's very similar to netcat, but much more flexible.

<ul>
<li>it can <a href="http://stackoverflow.com/questions/1000674/turn-off-buffering-in-pipe/1005567#1005567">create ptys when needed</a>
<li><A href="http://dandelion-patch.mit.edu/afs/sipb.mit.edu/machine/penguin-lust/src/socat-1.7.1.2/EXAMPLES">lots of examples</a>
</ul>

<h3>better / more polished documentation</h3>
<ul>
<li><a href="http://www.dest-unreach.org/socat/doc/linuxwochen2007-socat.pdf">good presentation</a>
</ul>