Further to the air brush topic

Robert,
Deans suggestion on a long line is a good one, I would also add that it helps to roll the line up and let it drop. Sort of like rolling up a garden hose and storing on the side of your house. That way the air gets cooled down and the water is trapped in the hose by gravity. You will need to blow the line out ever so often or you will get water sputtering out .
Also, if this is your first attempt air brushing, keep in mind that nailers require a higher pressure than an air brush. The higher the pressure on the air brush the more likely you will have some orange pealing on your paint. I would keep the airbrush as low as you can get below 30 psi. Of couse, if you want to give your model a dusted look, you can turn the pressure up a little over 30 psi and hold it farther from the object.

Mark,
The traps that I've always seen in the cabinet shops I work at are made of copper pipe. The are always bent to form either a spiral or a series of loops over a distances. I think this is the same method used by steam engines. They are usually combined with a filter but you're going to catch a lot more water from cooled down air than you can from air straight from the compressor.