NMap.org has created a neat visualization of the 288,945 largest sites on the web, as visualized by the size of their favicons.
The area of each icon is proportional to the sum of the reach of all sites using that icon. When both a bare domain name and its “www.” counterpart used the same icon, only one of them was counted. The smallest icons—those corresponding to sites with approximately 0.0001% reach—are scaled to 16×16 pixels. The largest icon (Google) is 11,936 x 11,936 pixels, and the whole diagram is 37,440 x 37,440.
They’ve got a dizzyingly large, interactive version at their site, which you can zoom into to your heart’s content. (Note that as of posting, it’s running very slowly, probably due to its popularity.)
Want a better explanation of what you’re seeing? NMap has also put together a poster that runs you through the 70 largest sites; click here to check it out. If you feel the need to Google ‘em as you see ‘em, be advised that site #62, xHamster, is not the friendly Hampster Dance knockoff you might expect from the name.