TrainPlayer

TrainPlayer is a model train layout and modeling tool for people who are really into model trains. You can download (i.e. purchase) a variety of track layouts, or even design your own with the accompanying TrackLayer, and then run your trains. The graphics are relatively simple; it's not really a game but rather a design tool "for the evolving railroader -- one who stares at track plans and dreams of an empty basement."

There are several editions of TrainPlayer for Mac from $29.95 to 79.95 and a demo is avaiable.

[Via MacNN]