What Fruit Did Adam and Eve Eat?

The Straight Dope has up a discussion of the various traditions for what is the actual fruit Adam and Eve ate in order to be tossed out of the garden of Eden. Western Art tends to depict it as an apple, but that is not what the text says.

Early rabbis suggested the fruit was:
- the fig, because the next verse mentions sewing together fig leaves to make loincloths;
- grapes, which later cause trouble for Noah, not to mention many other vino lovers;
- the citron, a lemonlike fruit which in Hebrew is etrog, a pun on ragag, "desire";
- wheat, khitah in Hebrew and thus a pun on khet, "sin" — a stretch, considering wheat isn't a fruit and doesn't grow on trees; or
- the carob, because in Hebrew its name puns on the word for "destruction."
Many modern scholars think the author(s) of the text had the pomegranate in mind.

Or, of course, it could have been a truly unique tree-born sweet thing. But either way this is interesting and something I never thought through before to this level.