Jack Naugler

Arduino micro controllers are an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists and anyone interested in creating interactive objects or environments.

This talk discussed a variety of opportunities to add motion to model railroads.

See much more at Arduino

The following video introduces the concepts of Arduino controllers using small servos such as those found in model airplane hobbyist stores.

Basics of Arduino Controllers for Model Railroaders

Here is another site that has specialized electronic controllers for model railroaders:

Tam Valley Depot