Continetal Airlines provides these very high quality headphones on the airplane which have a really ugly dubble mono = stereo plug to prevent you to use these nice headphones somewhere else than in the airplane. But recently I found out that this dubble plug perfectly fits into my laptop headphone and microphone input. This turns the Continental Airlines headphones into a perfect high quality headset! You just have to abuse one of these small speakers as a microphone.
(Yes, I know you have to shout into that little speaker and the quality is really poor, but it does work!)