UPDATE: Please note that Craigslist is blocking Yahoo Pipes. Until this changes, the solution posted here won't work. Please contact Craigslist & ask them to unblock pipes access and/or ask them to beef up their search system.
Craigslist.org is a great commercial free website for connecting local buyers/sellers. But if you've ever tried to put create a custom Craigslist search, you might be frustrated by the inability of Craigslist to handle complex searches with multiple custom criteria (e.g. cars under $5,000 made by Honda, Toyota or Nissan).
