I found some cool Google S2 favicon extractors, a script for Wordpress and a bookmarklet on Reddit for grabbing the favicon off of the compatible site you're on. A typical example of the Google S2 favicons usage is for displaying icons next to certain links just like these...
Here is a realtime script to help get the favicon link. Simply type in a domain and hit enter. The favicon preview is generated which you can right-click or drag 'n drop to save image. Optionally, an HTML img tag is generated for easy copy & paste.
HTML code for favicon image
Some domains show up as a default globe icon because those sites have not set it up accordingly. Try adding a favicon to your blog eg. http://yoursite.com/favicon.icogs2.js