From SFGate:

"FBI agents and British anti-terrorist officials, meanwhile, have concluded that the shoe-bomb plot originated with the ideas of [Ramzi] Yousef, an early al Qaeda operative who suggested flying passenger jets into buildings......Having obtained Boeing blueprints, Yousef calculated the most devastating place to detonate his bombs was in a seat above the center fuel tank, adjacent to the wing. The bomb alone would not destroy the plane, but it would detonate the fuel, ripping the jet apart. Reid, perhaps following Yousef's example, chose a window seat close to the Boeing 767-300's fuel tank."

Boy, I sure hope somebody is checking the passenger list for the famous TWA flight 800....