I generally write my constructor functions so I can easily forget 'new':

  function Point(x, y){
    if (!(this instanceof Point)) {
      return new Point(x, y);
    }
    this.x = x;
    this.y = y;
  }

then you can just call:

  var point = Point(x, y);

HT to issacs (node, npm) who I picked that up from.