What can I do with an RPi that I can't do with a laptop + Arduino?

@wildbill- avoiding the hijacking of this thread, the neighb is buying from http://www.strikemodels.com/; expected delivery is months from now. The guy builds the ship(s) with custom created 'guns'. My neighbor and I have high expectations for this project. We'll fine tune his before building more for our other neighbors in a pond of WAR. If Robin doesn't mind, I'll return back with a simple blog link (if I find the time and ambition to create one).