equivalent.js

app.get('/help', function(req, res){
  res.send('some help');
});

app.get('/search/:query/p:page', function(req, res){
  var query = req.params.query
    , page = req.params.page;
  res.send('search "' + query + '", page ' + (page || 1));
});

router.js

function Router(obj) {
  this.methods = obj;
  this.route(obj.routes);
}

Router.prototype.route = function(obj){
  var self = this
    , routes = Object.keys(obj);

  Object.keys(obj).forEach(function(route){
    var parts = route.split(' ')
      , method = parts.shift().toLowerCase()
      , path = parts.shift()
      , fn = self.methods[obj[route]];

    app[method]('/' + path, function(req, res, next){
      var args = req.route.keys.map(function(key){
        return req.params[key.name];
      });
      fn.apply(res, args);
    });
  });
};


Router.extend = function(obj){
  return new Router(obj);
};

usage.js

// GET /help
// GET /search/foobar
// GET /search/foobar/p2

var router = Router.extend({
  routes: {
      'GET help': 'help'
    , 'GET search/:query': 'search'
    , 'GET search/:query/p:page': 'search'
  },

  help: function(){
    this.send('some help');
  },

  search: function(query, page){
    this.send('search "' + query + '", page ' + (page || 1));
  }
});