Always good to see at Didcot museum, when the steam locos are operating, the passing trains on the Didcot Avoiding line give a hoot, and the steam loco responds. There are always some parents who explain to their four-year-olds, clutching their Thomas books, that the locos are saying Hello to each other, and a nice look of amazement in return!
Alas the real classic has gone nowadays, of at midnight on New Year's Eve someone jumping into every cab of the locos in the depot and sounding the whistle. Meanwhile all the date-expired detonators would be strapped to the tracks and someone would drive up and down over those. At Taunton at the end of steam in the 1960s the sound could be heard all across the town.