Ran into a bit of a problem on a side project recently.  Not all the members of the team had IIS on their machines so some were using ASP.NET Development Server (Cassini) to serve up the web services layer that I’d written.  The problem that they ran into was every time they restarted their project Cassini would fire up and serve the web services on a different port number.  I dug around and this MSDN posting on specifying a port for Cassini is the best info that I could find.  I’ve passed the info on and we’ll see if it helps out.