[peter_l_downs]

It can also be nice when you're writing instance methods on a prototype. for instance:

    var Person = function(name) {
      var self = this;
      self.name = name
    };

    Person.prototype = new function() {
      var prototype = this;

      prototype.sayHello = function() {
        var self = this;
        return "Hello\n\n-- " + self.name;
      };
    };

    var me = new Person('Peter');
    console.log(me.sayHello());

Obviously that's a pretty contrived example but it illustrates the idea. It makes it really clear exactly what "this" means at different points in your code. As a bonus, if I had to reference the current context inside of a prototype method, "this" is now available.

[bshimmin]

I don't like `var self` at all and I find there are vanishingly few places where you can't just bind a function appropriately, but one important thing to note, if you do go down this route, is that `self` is an alias for the `window` object, so if you happen to miss out that `var self` assignment at some point, you may get unexpected results.

On that basis, if you must do this, I would suggest `var _this`, `var scope` (though that would probably be confusing if you had the misfortune to be using Angular), `var me` (unless you happen to find anthropomorphism distasteful) or... well, anything other than `var self`, really.

[peter_l_downs]

Interesting, I never knew that `self === window` – thanks for bringing that up. I'm not particularly attached to the name, just wanted to show an example where assigning `this` to some local variable is useful.