Finally like Yahoo's site explorer, Google webmaster tools will tell you how many links are pointing to your site. A more accurate picture than using the link: operator command on Google search. Strange to see Google catch up to Yahoo on this front.
I definitely not perfect yet but it is cool how it shows you internal as well as external links for a domain - here is an example for Branica:
You can get more details on this great post that goes into all the details:
http://searchengineland.com/070205-165836.php
One thing that it does now show is how many unique domains are linking back to you site. Well with a little Excel twisting, it is easy to find out by exporting out the full external link table. Now I know that I have 528 domains pointing back to Branica. Are you one of them?
Seriously if you are not using Google Webmaster tools, you are really missing out on some great information for your sites. Well unless you are using blackhat techniques for a site then maybe it is not such a good idea to use Google Webmaster tools for that site.