I think a very ambitious but needed project is an automotive assembly plant. It would be huge, but also employ lots of sims and also greatly increase industrial demand because so many suppliers locate near these facilites. I have toured the Saturn plant in Tennessee and was very impressed. If you wanted one industry that can change a communitys economy it would be an auto assembly plant. I also think it should be ploppable but very expensive because towns have to give up big bucks to recruit one of these plants. There are lots of pictures and diagrams of various plants at: http://www.autointell.net/nao_companies/american.htm