In my post of 23 March I mentioned the Virtue - 100 Top Social Brands Index. As you possibly remember the nr 1 social brand (i.e. the brand most mentioned in Social Media) is iPhone followed by CNN and Apple.
In the site of Vitrue you can now find a very useful gadget measuring and comparing the "socialness" of brands. Interestingly the name of the American President Obama seems to be more popular in social media than even iPhone.