HuskerN, you're right about small amounts of paint used for airbrushing. I often only use half of an eye dropper of paint in the airbrush. I still use a jar under my airbrush, but I also do have a cup (much smaller than the jar). But IMO, either one is just as easy to clean. I don't see a problem with using the airbrush for small jobs like that.
Have you considered installing a paint booth to be able to paint (airbrush and spray cans) in your workshop, all year around?