allow variable host as second argument

server.js

@@ -7,12 +7,13 @@ var util = require('util'),
     events = require('events');
 
 var DEFAULT_PORT = 8000;
+var DEFAULT_HOST = 'localhost';
 
 function main(argv) {
   new HttpServer({
     'GET': createServlet(StaticServlet),
     'HEAD': createServlet(StaticServlet)
-  }).start(Number(argv[2]) || DEFAULT_PORT);
+  }).start(Number(argv[2]) || DEFAULT_PORT, argv[3] || DEFAULT_HOST);
 }
 
 function escapeHtml(value) {
@@ -38,10 +39,11 @@ function HttpServer(handlers) {
   this.server = http.createServer(this.handleRequest_.bind(this));
 }
 
-HttpServer.prototype.start = function(port) {
+HttpServer.prototype.start = function(port, host) {
   this.port = port;
-  this.server.listen(port);
+  this.host = host;
-  util.puts('Http Server running at http://localhost:' + port + '/');
+  this.server.listen(port, host);
+  util.puts('Http Server running at http://' + host + ':' + port + '/');
 };
 
 HttpServer.prototype.parseUrl_ = function(urlString) {