Function.bind.js

// http://jsperf.com/function-proto-bind/3
Function.prototype.bind = function(that){
    var self = this,
        args = arguments.length > 1 ? Array.slice(arguments, 1) : null,
        F = function(){};

    var bound = function(){
        var context = that, length = arguments,length;
        if (this instanceof bound){
            F.prototype = self.prototype;
            context = new F;
        }
        var result = (!args && !length)
            ? self.call(context)
            : self.apply(context, args && length ? args.concat(Array.slice(arguments)) : args || arguments);
        return context == that ? result : context;
    };
    return bound;
};

You dont need to create F function every time. You can create function once, and then set prototype and construct the function and the prototype will be frozen for that instance. It's like 3 times faster.

I know that it also applies to reset() function of mootools Class