nestedapps.js

// HOPED-FOR BEHAVIOR: /cats says: Cats Home
// ACTUAL BEHAVIOR: /cats says: Main Wildcard

var express = require('express');

var app = express();
app.get('/', function(req, res) {
  res.send('Main Home');
})

var catsApp = express();
catsApp.get('/', function(req, res) {
  res.send('Cats Home');
})
app.use('/cats', catsApp);

app.get('/*', function(req, res) {
  res.send('Main Wildcard');
});

app.listen(3000);

Post here: http://justjs.com/posts/creating-reusable-express-modules-with-their-own-routes-views-and-static-assets

Other gist here: https://gist.github.com/boutell/4423473