How big is the Second Life landscape?

When measured on a square mile basis, Second Life has already grown enough to be considered bigger than New York. Now that's not only quite impressive for a place that does not exist in the real world, but also when you take into consideration that according to Wikipedia, New York has been the largest city in the US since 1790 and its 8.2 million residents reside within a 332 square mile footprint. Second Life, on the other hand, was only launched in 2003 yet has a population of more than 13 million and covers an astonishing 462 square miles and that virtual land mass is growing at a rate of 5 percent month on month.