In this article I used the cloud effect birdunyadusun.com site will explain the technique.
Some sites have similar made with Mootools. I did research in jQuery forum. No information about the coding of similar applications. This article has nothing to parallax technique. Let's start coding.
The following code will load the clouds just below is a description of the body.


<span id="spnCloudHolder"></span>

And using this javascript codes for generating clouds:


$(document).ready(function() {
    for (var i = 0; i < 3; ++i) {
        $("#spnCloudHolder").append("<img src=\"img/bulutcan12.png\" class=\"cloud\" />");
    }
});

 

You can use this image file(Transparent PNG, thanks gündüzhan):

Output current screen:
More...