Get rid of the boring default icon on your website. Add a custom icon! Most browsers support .ico and the most popular ones will show any standard web image.
Follow this easy step by step to add one to your web page or site.
Example: This is Prestwood.com's icon. 
Images must be 16x16 pixels. I use GIMP to create mine.
Normally, save as a .ico file in the root of your site or in any unsecured folder. I usually put them in "/images", and I usually name it favicon.ico or favicon.gif.
Add this to the header section of your AJAX Master page or any aspx/htm/html/shtml page.
<link REL="SHORTCUT ICON" HREF="/images/favicon.gif">
Some browsers even support ANIMATED gifs.