Recently I’ve read a book: High Performance Web Sites written by Steve Souders (Chief Performance Yahoo).

After reading this book I’ve apply some optimizations for the improvement of the download speed  in different browser. One in particular i want to talk about is reducing the http requests by using one simple css image (css sprite) for the the entire  layout (if simple one). Normally the browser can do a limited numbers of http request at the time , some 4 some 8 some more, depends on the browser and browser version. If i have one big image for the layout, i will have only one http request instead of 20 or more. Another thing that I’ve notice  is that 20 small .gif or .png images weighs more (3-4 times more) than the single big image so in terms of band usage you will gain also. When you do such a simple optimization the benefits are a lot, because you live space for http requests for other elements that need to be downloaded such javascripts, html or others.

I’ve created a layout using a css sprite image here Chamonix Guide and the image is this one

To test your site and see ho many http request are made on the page load you can use yslow