Trader Joe's and Costco were two that consistently came out on top. (For what it's worth, I've been buying the Costco organic EVOO and it's been great. I'm a supertaster and can--fortunately or unfortunately--taste the difference.)
also, is lifehacker becoming the next about.com? seems like anyone and everyone can write for it, and i found their content to be pretty cheap these days
(Tom Mueller is the source for this article and he's been at this for a while, having written an article on sneaky olive oil producers for the New Yorker in 2007.)
He also has a buyer's guide on the same site and it sounds like, at his level, buying olive oil is trickier than buying wine. Not only is it dependent on harvests and growers, it is also perishable.
Also the bit about prices going down being caused by the fraud is far from factual. Doesn’t mean it’s untrue, but it’s a designed as a story with a moral at the end, not a study.