Composting worms, like chickens, probably won't make you rich, but they are a cheap, fun and easy way to cut down on your monthly (garbage) bills. A well-established colony of red wiggler or European nightcrawlers, the two most common types of composting worms, can eat their own weight in food waste every day. Your garbage won't smell (there won't be anything in there to stink it up), the lighter bags will be easy to carry to the curb on trash day, and every month or two you can harvest the worm poop to use as plant fertilizer. It's hard to find better fertilizer than worm poop.
You can make a worm bin out of cheap storage bins or spend $100 or so on a custom-made setup, which often comes with stackable trays and liquid collecting tanks. A well-kept worm bin won't smell and can be kept under the sink or in the corner of the kitchen.
Red Worm Composting is a great place to get started with worms. They sell both kinds of composting worms as well as bins and books on the best ways to take care of your little wigglers.