Best anorak?

stamp collectors.

I once said something offensive about train-spotters at a party (oh, the demon drink!). I got a dig in the ribs and it was whispered in my ear that the bloke I was talking to WAS one. "Of course," I continued "It's not as bad as being a BUS spotter." Another dig in the ribs. Guess what, he was one of them too. I changed the subject and asked him about his most recent holiday. The Alps. Oh good, we're on to promising territory. I asked him what he got up to. It turned out to be a hot air balloon spotting adventure. I got my coat.