Jet Blue has the right idea, with their standardized increase in leg room throughout their entire fleet, though they only fly domestic US routes.
If you've ever been stuck in the middle seat of the middle section of seats on a flight from Heathrow to San Francisco, you know the meaning of "in-flight torture". Especially if you're 6 feet, four inches tall and not getting any younger (yours truly).
Kerry Stowell gives some practical tips in a new monthly feature article at TouristTravel.com. Read the full article here before you embark on your next long distance airplane ride.