17th
Google Browser Size - Latest release of Google labs
Google Browser Size is a visualization of browser window sizes for people who visit Google, or any other site where the content is principally aligned top-left (so not like mine here).
It is still a basic tool that can merely only be used on Google, as what users are seeing (or at least what grabbing their attention first) in a page depends greatly of its content, its density, positions, heading sizes, use of images, icons, etc.
I’m enthusiast to see future development of this tool as it can really help all of us (interaction designers) explaining quickly to a client what users are seeing or not depending of user screen resolution and browser size.