I recently tripped across a really cool site the helps to build trust between buyers and sellers on classifieds sites. The site is called Faceified. It enables sellers to register their ads ans ask for reviews from buyers. Sellers can then refer future potential buyers to the site to read about their reputations and reviews from other buyers. It is a step in the right direction in terms of knowing who you are buying from and selling to on online classifieds sites. Worth a look. www.faceified.com