Actually, in the three years since I posted this, it has become more difficult to tell which books have been written by space aliens instead of human beings. But the examples provided still hold true.
Thing is, more and more people nowadays behave like space aliens! I mean, would genuine earth people sit together around a table, on the sidewalk outside the pizza parlor, and instead of talking with each other, just sit there transfixed by some electronic doodad? (Please say I’m right.)