This is called RSVP. It is easier (for the same WPM) with 2-4 words at a time than 1 word. I really hope this catches on more and allows different chunk sizes.

500 wpm with no training is an exaggeration. wpm also depends a lot on which book you're reading. however, RSVP is the fastest way to read and way over 500 wpm is possible with practice.