The local buses around Heathrow are only free within a certain radius, check carefully or you could be up for fare evasion. Very useful if you know the system, but going back to the airport usually requires a walk along and across Bath road.
Chinese airports have hot and cold water dispensers available so you can avoid extortionate prices by bringing your own mug and tea bags. Unfortunately passengers then think they are free to use the aircraft galley as well.
Another thumbs up for the Three Magpies, but how does it get so crowded when it's almost in the middle of nowhere ?