Much has been said about the brouhaha surrounding the PZ Myers - Webster Cook - Catholic Church story.
I don't know if anyone has ever suggested it, or if it has been done, but I don't see why it can't be settled with good ol' scientific observation.
Get a couple of transubstantiated wafers test them against a couple of others from the same lot of crackers...check the atomic structure. Therein the truth lies.
Now THAT* would be interesting.
*THAT being the worldwide religious fallout when the crackers are proven to be...well...crackers. I got your shroud right here, baby.