As a female, I'm very careful about any dealings that I make on CL and use my common sense. Like sporty said, always meet someone in public regardless if you're trying to sell or are trying to buy something. Starbucks is a good place, as there is usually one in every town.
I don't think I'd ever try and sell anything that is small and valuable there because I think it would be just to easy to be stolen from. This is just from a female's perspective, maybe you burly men have a different viewpoint. :)