A conversation about wanting the window seat over the aisle in an airplane reminded me of this photograph I took when flying into
Besides being a landmark for pilots and a location hunt for google earth users, NASA uses the letters to calculate "spatial resolution for lower contrast vegetation boundaries" in images taken from space.
Check out the bottom of the page for their technical uses of the 3,000 foot letters.
A commenter on Google Sightseeing calculated the font to be a 1,468,800 point size.
The moral of the story is that window seats are more entertaining.