U-Exchange: Sway just about anything

You can search for items around the world using U-Exchange. They're up front about spotlight advertising by businesses, which is a plus in my book.  It helps keep the site free. I like that my email isn't available and that we have to use verification codes to post/send email.  People have pretty neat items they want to get rid of and I don't have to pay to browse listings (window shop before you ask for items). People even trade services. 

Swap Mamas

I love the idea behind Swap Mamas: give/swap your children's items and save money.  It's also green:).  I'm not a fan of the giver paying shipping, even though I understand it makes everything totally free.  They have a great online community that can be taken offline too. Plus, I give props to anyone who was laid off that creates something that does good for others.