middlleware that catches stuffs the router didn't serve.

afterouter.js

var express     = require('express');

//Create the express app;
var app = express.createServer();

app.use(app.router);

//You place this middleware right after your router so paths that the
//router can't match will go through it and finally end here.
app.use(function(req, res, next){
  //There you can render a view or put a 404 error page, anything you want.
  return res.send('Hello this is my static page');
});

app.listen(3000);