This just in from TheLobby.com blog (presented by Starwood Hotels):

A New York Times reader recently asked a question that has been on the minds of many of us persons of height: Can tall people reserve special seats on flights without paying business-class fares? The answer is that it varies. Certain airlines, such as Taiwan's Eva Air, Virgin Atlantic, British Airways and United Airlines offer special "medium-range" seating for around one-third the price of a business-class seat that include up to seven inches more legroom than normal economy seats. New start-up MAXjet, a business-class-only airline that limits its flights to the JFK-Heathrow and Dulles-Heathrow route offers standard seats with 60 inches (!) of legroom as well. For other airlines, well, there's always sweet talking your ticket agent. It might be a bit old fashioned, but it does work more often than one would think.

Good to know for those of us who have to occassionally fly commercial and are NOT vertically challenged.