how big would the Gulf Oil spill be if centered in Louisville? how great (in size) is the Great Wall?

From Alissa Wilkinson in World on a BBC project called "Dimensions" at howbigreally.com...

...hearing or reading about the size of an event or place is nothing like seeing it for yourself...

Want to know how the moon's diameter compares to your hometown? Interested in seeing how much of Europe the Gulf oil spill would cover? Curious about how ancient Constantinople's size squares with Texas? Simply choose what interests you—say, the Great Wall of China—then punch in your zip code or the name of the town, and see an illustration laid across the map....

Centered in Louisville, here's the Gulf Oil spill and the Great Pacific Garbage Patch.