I tend to perfer the homemade solutions to this problem as they work as well as the ones you can buy and are mostly lots cheaper.. although I am keeping my eye out for a cheap lazy susan...
Here are my favorite airbrushing jig solutions.....
#1 is the basic popsickle stick you get at crafts stores.. with masking tape.. works great also with spruce bits..
#2 is a strip of aluminum bent in half... would work well with auto bodys... or any large part with a body opening like a tank turrent ring... micro mark sells a simular item for $15.. but if your a good scrounger you can get a peice of alum for free or at most a couple of bucks.. and if you want to get fancy you can drill a couple of holes and add the tensionar bolt....
#3 is my personal favorite.. It is a block of wood with several lines of holes drilled in it.. the holes are just the right size for a woden rod to fit inside.. I personally use the long wooden q-tip rods as they are perfect for most things.. I either stick the parts directly on them like the roadwheels of my M-10 or cover them with tape and stick the small parts on them that way.. I mostly use it for wheels of various types.... you can also use small dowel rods to get other sizes.. i plan to make one that will be able to fit most sizes of wheels on it.. its very handy for that as you can paint both sides of wheels without stopping... or a part where you have to paint all of one side and most of another.. you get the picture... and the wooden block holds them so that they dont' hit anything esp when you move them around.