router.js

var router = exports,
    fs = require('fs');

router.init = function(parent, map) {
    var controllers = [],
        _this = this;

    function _loadControllers() {
        fs.readdirSync(parent.get('controllers')).forEach(function(name) {
            controllers[name.replace(/\.js$/, '')] = require(parent.get('controllers') + '/' + name);
        });
    }

    function _setupRoutes() {
        var route,
            routes,
            routeVal,
            path,
            method,
            controller,
            fn;

        for(method in map) {
            if(map.hasOwnProperty(method)) {
                routes = map[method];

                for(route in routes) {
                    if(routes.hasOwnProperty(route)) {
                        routeVal = routes[route];
                        path = routeVal.split('/');

                        if(path.length > 1) {
                            controller = path[0];
                            fn = path[1];
                        }
                        if(typeof(controllers[controller]) != 'object') {
                            throw new Error(parent.get('controllers') + '/' + controller + '.js does not exist.');
                        }
                        if(typeof(controllers[controller][fn]) != 'function') {
                            throw new Error(controller + " controller doesn't have a method named '" + fn + "'");
                        }
                        parent[method.toLowerCase()](route, controllers[controller][fn]);
                    }
                }
            }
        }
    }

    _loadControllers();
    _setupRoutes();
};

usage

var router = require('./libraries/router');

app.set('controllers', path.join(__dirname, 'controllers'));

router.init(app, {
    'GET': {
        '/'          : 'index/index',
        '/login'     : 'account/login'
    },

    'POST': {
        '/login'     : 'account/authenticate'
    }
});

Thought this would come in handy to automatically load controller files and set up routes..