Where your favourite browser doesn't have access to enable and disable features so quickly (eg. Internet Explorer) we can add bookmarklets to the "favorites" menu that allow us to quickly see what our web page would look like with various configurations.
You probably see your web page as you intend for it to be seen with all of the images where they are intended to be. Others may have images disabled in their browser or may be using a browser that doesn't support images at all. Do you have any idea what your page might look like in those browsers? We can simulate those situations with a couple of bookmarklets. This first booklet will allow you to see what your page looks like with the images completely removed the way it would be seen in browsers that ignore images completely (to install it simply right click on the following link and select "Add to Favorites").
Of course in a browser where images are just disabled the page may still be laid out correctly but with just a blank space where the image should be. The following bookmarklet (installed the same way as the one above) shows you what the page might look like then.
You may need to refresh the page in between to get the images to reappear if you intend to use both on the same page.
This article written by Stephen Chapman, Felgall Pty Ltd.