I’m glad to run across this, from Sarah, 7 October 2002, since I can never remember the site: "For my pal with hugely long legs and the broadest of shoulders (all the better to bear the weight of the world): SeatGURU. They have seat space ratings for lots of airlines and airplanes."
They rate the seats by desirability according to various reasonable criteria, and show the location of power points, enabling me and my fellow traveller to watch Dr Who on my laptop all the way home during our last air trip.