Most people just want to check the page rank and so I think it is fine with all the adverts etc, people will use site if the functionality works. Good luck with it.
Well No doubt the tools are useful but page appears to be a page of newspaper,the basic design methodology suggest that it should be more user friendly.I think if you can rearrange the check pagerank bar a little low or without being surrounded by those google ads it will make it more visible . Visibility and accessibility is the most important aspect of a good design . Well for the ads you can have a sidebar or may be two sidebars that will clean the main content page and also the ads will be visible . The audience or visitors coming to your website should feel that the tools are for there importance . If you want people to return to your website , you should make them feel comfortable.And that can only be achieved if we have a simple neat and clean look and the things are not confusing . I have just presented my view , please dont mind.
I like the output...the PR at each data center...very cool. But I agree with the comments about the input page. Give the area around the input box a little space. And not everyone is a savvy as the people here so a sentence or two giving instructions on what to do wouldn't hurt