portions of your Web page most visible by the average user

Website Magazine has an article about Google Labs new tool that will show the portions of your Web page most visible by the average user.

Snip>>>
Browser Size overlays a map of sorts, showing percentages of typical users and what they will see on your page ... It provides a nice snapshot so you can see if the most important parts of your page - calls to action - are being seen immediately by the average Web surfer.

Your can read the whole article (New Google Tool Tests Your Page for Calls to Action) Here

hth ~megan