There was a recent query on How to add "Logo" on the "address bar" of your website url
The process is quite simple really.
All you need to do is create a really small image size logo of yours say 16X16 pixels. Take it to Image editing software like Photoshop and save as any gif image etc.
Upload the file using a site builder or any FTP into the root domain directory of your website and rename the extension of the file as an ".ico" file
Refresh, save and now load your url on Firefox Mozilla and you can see your logo on the url.
Note: Many a times the logo is still not visible in IE but can be seen in Moziall etc....