Are Blueberries a Good Source of Antioxidants?

Your Allergy Dude attended the Blueberry Festival at Roper Mountain Science Center today.  One of the vendors said to me, "Remember, blueberries are a great source of antioxidants."  I also remember reading this on a bag of dried fruits.  So I asked myself, has this been measured objectively and what does this really mean?
Yes, blueberries are very high in antioxidants.  The highest fruit, and second only to beans.  The theory is that aging and diseases result from oxidation of naturally and normally functioning chemicals in the body.  So something that reduces or prevents oxidation would be a good thing.  The amount of antioxidant activity is measured in vitro, that is, in the laboratory using oxygen radical absorbance capacity (ORAC).  This sounds good, however, the Allergy Dude must point out that the numbers produced have unfortunately never been shown to be clinically significant.  I would like some further justification for trying to eat a healthy diet.
Photo 2 reminded me, in their garden, but not their spice garden because I forgot to take a picture there, that spices have been measured using ORAC to have antioxidant activity also.  However the minute amounts used in regular cooking translate into little net antioxidant activity.
Like your Allergy Dude has said before, eat a healthy diet, because you are what you eat.