Side businesses are getting a lot of interest by people today in the U.S. Partly it seems to be due to the cachet that owning your own business has. Everyone from Martha Stewart to Donald Trump wants to be called an entrepreneur. Being American, we want it all, of course. So even if we have to keep our day jobs out of economic necessity, we want to be entrepreneurs, too. Hence comes the interest in side businesses. Not to mention that there's the chance to pick up extra cash, something that everyone likes. Entrepreneur.com has a slideshow outlining ten low-cost side businesses you can start and run on weekends. Among the businesses are storm window installer, pet sitter and vending machine operator. I have a tip for triggering ideas for side businesses: if you know any firefighters, watch what kinds of businesses they have on the side. Or ask them what the others at their fire house do on the side. In many jurisdictions firefighters work a schedule that is is 24 hours on, 48 hours off. As a result, many firefighters have side businesses. Often these will be unique niche businesses. For instance, way back when waterbeds were a big thing, if you moved house you had to drain the waterbed -- not a pretty picture for the average homeowner who doesn't know what he or she is doing. I remember the moving company we hired recommended a guy whose side businesses was draining and then setting up waterbeds again at the new location. Talk about a niche. Guess what his day job was? A firefighter. All those little headaches that people don't like to do or can't do on their own can be the foundation for side businesses.