Just a quick heads up to Favico.js, a fantastic JS library that lets you do all sorts of awesome stuff with your site’s favicon.
You may have noticed a number of popular web services like Gmail and Facebook have this already to notify you of new messages and such. Now you can add it your site too thanks to the work of web and mobile developer Miroslave Magda. Kudos.
Have a browse through all the various options, from slide animations, pop animations and even video.
If you experience any problems, another alternative worth checking out is Tinycon.