Stupid Mirror Question

 From:  Phil (PHILBO)
So I made a fuselage for a spaceship and modeled the front wing, rear wing and everything perfectly. I now want to mirror it to the other side of the craft. I can get the whole thing mirrored but it appears to be two different objects. One with the left wings and fuselage and one with the right wings and fuselage. I cannot get them to join together with the boolean command. I want it to be a single object. How do I go about getting this done properly? Should I cut the fuselage down the middle and then mirror and somehow fuse the two together?

Thanks for any help that you can provide quick since the file must be sent out for rapid prototyping tomorrow.