I accidentally stumbled onto a link for rail museums recently and then started looking around where I had landed. I was somewhere on http://www.railserve.com. The category menu had a pretty good selection of all things trains, from models to 12":1', and then some. Then I saw the entry, "LEGO Train Clubs & Layouts". Hey hey, brick built trains are catching the indexing of mainstream (mainsteam? mainline?) railfanning. A few dozen links, most familiar to the readers here, but there might be a few surprises. Nothing is perfect though, as of this writing they still need an entry for RailBricks (grin), but I submitted that request.
For more, see http://www.railserve.com/LEGO_Trains