I had a conversation with Joe over at Urban Outsitters this morning when I picked Parker up. It seems he's had run-ins with Yelp as well. He mentioned a ratings service that, he thinks, actually works: Angie's List.
The difference? Angie's List members have a reputational risk of their own when posting. The members may be anonymous to the vendors they're rating, but they're authenticated, and can be held accountable for their content. Also, the List, being member-financed rather than advertiser-financed, has no potential conflicts of interest. Yelp and other advertiser-supported media always have a potential for payola. Always.