Besides being a great place for telescopes, you could mine the moon. Launch the metals into orbit with nothing more a linear accelerator and then foam it before landing it into the oceans for pick up. (Foaming a metal on earth is not as easy as zero G). You could also use that launcher as a cheap and potent weapon. Talk about King of the Hill!
The moon could even become a gas station to the rest of the solar system because of the ice buried in the polar craters.