You can buy canned air that connects to a paint sprayer. Its fairly cheap and is the way I first started painting up a few of my lures. It won't get near the detail of an airbrush, but is pretty fun to just tinker around with your baits to see what you come up with. Here is a link to the sprayer:
http://greens-garage.com/index.php?main_page=product_info&cPath=1&products_id=8