I'm late to the game on this, but I'll give a shout out to Google Sightseeing as one of the better time sinks as of late. I've been particularly intrigued on the discussion of several strange points found on the aerial photos. They first were found in the West Palm Beach area of Florida, but have more recently been spotted in LA (links in this comment). As of yet, no experts seem to have weighed in.
Anyone know someone in the aerial surveying industry?