I read a review of this book in the NYT recently and it made me paranoid about my olive oil so I picked it up. It's scandalous what is sold as olive oil - a horrendous amount of what is labeled as "extra virgin" is not, and Mueller makes the point that the real deal is worth getting - it is more flavorful and healthier that the olive-flavored mixed-source oil that's sold as EVOO - but which isn't.
His website provides a handy reference for places where you can get the good stuff - fresh oil that's unadulterated, protected from light, heat and oxygen and bottled individually. After all, olive oil is actually a fruit juice, and he emphasizes that it doesn't get better with age, and it's life is measured in months, not years.
I went to one of the places he recommends (actually I'm not sure it's listed since I just realized I confused it with the Oil & Vinegar franchise in Allen) Lover's Lane Olive Oil Company in Dallas, where they have a couple dozen oils you can sample, and fell in love with an Australian plain oil (not flavored with herbs, as many they have are). I went through a bottle in two weeks, and went back Thursday to refill one (saves six dollars a bottle when you refill the bottle) and buy a second. Ever since I got that first bottle I can't get enough - I am dipping enormous amounts of bread in it, and I dress salads with just oil now because the vinegar competes with the taste. This stuff is spicy-tasting, and just ridiculously good with some dipping spices and good, hot crusty bread.
Anyway, great book. Go buy some of the good stuff and see what you're missing.