For the sake of completeness and just to confuse rav a little more, I might add that in England a common term for anyone who is highly involved in their hobby can be prefixed or suffixed with trainspotter. Trainspotting, i.e. the collecting of endless info on trains, is of course the archetypal nerd hobby, bar linguistics :-) So, for example, those who go to clubs and spend all night looking over the DJ's shoulder at the records played are called 'trainspotter clubbers' and someone who is obsessed with the Queen would be a 'Queen trainspotter'.