This is very simple, both in concept and in execution, but it turned out great and I couldn't find anything quite like it here, so I figured I'd share.
My wife and I recently moved into a typical downtown apartment: great location, not very much space. The apartment only has one tiny closet, and we just didn't have room for all of our clothes. Initially, we considered buying a set of shelves to put on top of our chest of drawers, but the fact of the matter is, we're both really short, and those high shelves wouldn't be of much use. Hence, the idea to make a clothing rack out of threaded pipe that could sit on top of the drawers.
Step 1: Materials and measurements
All you need are a few segments of threaded pipe, and the appropriate joints. I was able to find everything I needed at the local hardware store, where they were happy to cut pipes to the right length and put the threads on for me. I used 3/4" diameter pipe, largely because that's what my hardware store had. I think 1" pipe would work just as well, but thicker than that you might not be able to get the hangers over the bar well. Make sure all your joints match the diameter of your pipe!
ALL PIPES SHOULD HAVE BOTH ENDS THREADED
2x pipes the height of your stand, less ~4" (the bottom and top joints will add to the final height)
1 pipe the length of your stand, less ~4"
4x pipes 8" each, for the base (this is for a final base width of about 20", which is very stable on mine)
2x 90 degree elbow joints
2x tee joints
4x end caps (these are important, to make the base level with the tee joints; your rack will wobble without them)
Regarding the height of the rack: I measured it out so that my wife and I could both comfortably reach the top bar. I realized after it was assembled that it could've been significantly taller, because you hold the hanger from the bottom when you're taking things on and off the rack. This gives you about 9" more reach. It would've been nice to have those few inches, to make more room for storage underneath.
A small tip: my pipes came covered in grease, presumably because of the cutting and threading machinery. You'll want to clean them up well before doing anything with them!