Hi Mark, I think you're describing a favicon.
They're slippery fellers! Sometimes they'll stay on your favourites toolbar, next minute you've lost them all, but they do help promote an overall identity for a website (which is important in my book!)
Here's a thread that came up recently asking pretty much the same question.
icon in address bar
To summarise the steps...
First of all you'll need to make a favicon of your own. This can be based on your company logo, or an abstract image perhaps that relates to your site. There are a few sites offering to make you a favicon online. A WPW member,
graphicsguru has one such site at
http://www.programguru.com
Once you have your favicon, simply upload it to the root of your server and add the following line to the <head> section of your web pages. For XHTML, the code would be something like this:
Code:
<link rel="shortcut icon" type="image/x-icon" href="favicon.ico" />
NB: This presumes you've named the file "favicon.ico" and it's stored in your site's root directory.
That's about all there is to it! :o)
Hope that helps!
Paul