cps.js

// Continuation-passing style helper

var CPS = (function(){

    var slice = Array.prototype.slice,
        slice1 = function(args) { return slice.call(args, 1) },
        cont = function(fn, args) {
            args = slice1(args);
            return function() { return fn.apply(null, args) } };

    return function(fn) {
        cc = cont(fn, arguments);
        if (this instanceof arguments.callee) while(cc = cc());
        else return cc;
    };

})();


// Now can use 'return CPS(fn, [args])' for return continuation

function sum(n, cont) {
    if (n == 0) return CPS(cont, 0);
    return CPS(sum, n - 1, function(res) { return CPS(cont, n + res) });
};

// And 'new CPS(fn, [args])' for run your continuation-passing style function

new CPS(sum, 3000, function(res) { alert(res) });

// Also read http://mihai.bazon.net/blog/redis-client-library-javascript-node
// ...and have fun ;-)