Yoshie,
The "oldest 'People of the Book'" question (in Islam) is an open debate. You say it's Judaism. It may not be the Jews, actually, but natives of your beloved Iran -- Zoroastrians. Zoroastrian folks were often outright killed by Khomeini and many were forced to flee the country; from what I understand many still live on tenuous grounds there.
Below is from "Religions of Iran: Zoroastrianism":
"‘People of the book’ or ‘dhimmis’ (Zamis) in Quran are named as Jews, Christians and Sabians, who had adherents among the Arabs. To them Muslims presented three choices, death, conversion or the payment of tribute (jizya). To other infidels including Buddhists and followers of other religions two options were offered death or conversion to Islam. Zoroastrians theoretically belonged to the second group, however because of their sheer numbers Muslims were forced to regard them as dhimmis."
http://www.iranchamber.com/religions/articles/zoroaster_zoroastrians_in_iran.php
Tell me when you get it all figured out theologically. A local professor at Southern Methodist University, an Iranian and Zorastrian, didn't have many nice thigs to say about the way she and her family were treated in Iran as Zoroastrians, who claim (rightly or wrongly) to be the oldest monotheistic religion on Earth.
As far as I'm aware, Zoroastrians are still persecuted or at least marginalized in what should be their homeland, but the relative newcomer that is Islam.
-B.
Yoshie Furuhashi wrote:
"Among the religions of the book, the oldest is Judaism, so one might suppose that it is the most difficult to square with science and modernity, but it turns out not only that the largest branch of American Judaism, Reform Judaism, is perfectly capable of doing so but also that Reform Jews hold a more progressive foreign policy view than secular "Just Jewish" Jews (who are themselves to the left of most other groups in America), according to the AJC survey cited by a recent Ha'aretz article...."