wow, I wonder if these are offset for time at all, or whether there's any risk of terrorism, near airports. I guess not -- if you're close enough to be a problem, you'd see the plane, no? http://www.wolframalpha.com/input/?i=flights+overhead
I collect natural history, environmental, and geography books, almost compulsively. I look for used versions where I can (to save paper) but also appreciate that many of these books come out in runs of a few thousand copies, and aren't profit-makers for the publishing companies, so when they come out new, I buy them while they're new. If you like Geographile and want to let me know, please either comment on my posts, or visit my Powell's wishlist to feed my book collection. You might find books you like there, too.