[NB: This is part of an email I wrote a couple days after September 11 to a different friend (i.e., not Chad). I think a lot of us were wondering about God right around then. ]
Did God create evil? My own answer, which is that God isn't a literal anthropomorphic being (thereby making theodicy kind of a nonissue for me), probably won't help address your question, so let's take a more classical approach. Some ways to look at the question (and all of these are centuries-old points of view):
1. God created everything. Evil is a subset of "everything" in the Venn diagram, so the inevitable logic is that God therefore created evil. Even if Man "fell" during a primordial temptation, then there's still the question of the preexistence of the Tempter.
2. Some people say God didn't create evil. Evil is the result of Man's freedom, not God's design. This still means, of course, that God created a cosmos that has the potential for evil, which means he's still partly (or maybe fully) responsible for allowing it.
3. Some suggest (like St. Augustine) that evil doesn't truly exist (cf. his Confessions, Ch. 7, I think). Just as blindness is a lack of proper functioning in the eye, so evil is a lack of proper goodness (this is John Hick's reading of Augustine in his Philosophy of Religion). Others reply that this is an extremely dangerous interpretation of evil, for it means that something like slavery or the Holocaust or the murder of thousands of people at the WTC is just "apparent" evil, not real in any meaningful way. Are we truly ready to say such disasters are "apparent" evil?
4. Similar to (3) above, some look at evil and say that it's part of God's grand design. This has been called the "hidden harmony" defense of God. Things look chaotic and miserable from our limited human perspective, but if only we could see the cosmos through God's eyes, we'd see that all suffering has its proper place in the grand cosmic symphony. But as with (3), the rebuttal is that it's horrifying to contemplate the notion that something like the Holocaust (etc.) is part of God's divine plan as we march along in this "salvation history." Maybe this is how things work, but is such a God worthy of worship? You decide!
5. Some say evil is simply a necessary consequence of the gift of human freedom. God is available to alleviate our suffering, and perhaps God also suffers with us (Jesus might be considered the ultimate template for that line of reasoning), but God can't violate our freedom by puppeteering us. This, of course, begs the question of God's submission to logical necessity, for surely an omnipotent God can create whatever cosmos He desires—even one where people live the paradox/absurdity of being fully free and also free from suffering. Such universes are possible for a truly omnipotent God.
People create theodicies (theodicy = attempt to reconcile the existence of evil/suffering w/the traditional concept of an omnipotent, omnicausal, omnibenevolent God; more abstractly, it's simply an attempt to make sense of evil's existence) because they want to defend God. If it is somehow proved that God is ultimately responsible for evil/suffering, then one fears that this God might not be worthy of worship. There goes the universe.
I find this reasoning annoying because the scriptures show plenty of instances where God causes or allows suffering. The Israelites acquire their land largely because God allows them to slaughter the land's previous occupants. God threatens his own people with punishment if they violate his series of covenants. Going further than Abraham and Isaac, God sacrifices his own son on the cross. Lazarus is allowed to fester for four days just so Jesus' divine authority can be cogently demonstrated through a powerful act of resuscitation.
Job perhaps best expresses the attitude of the true believer in the face of the horrible divine mystery when, toward the beginning of the book, he moans, "The Lord has given; the Lord has taken away. Blessed be the name of the Lord!" All the whirlwind histrionics of Chapter 38 (etc.) notwithstanding, the authors of Job are not really interested in deeply probing the nature of God; they are, however, interested in exploring our faith-response to suffering.
It's interesting to note that, historically, Jews have been more willing to accept this apparent self-contradiction in God's nature. Elie Wiesel's Night shows poignant examples of this throughout. It's been Christians, though, who insist on a very narrow view of God's supposed "moral perfection," which usually gets defined as the impossibility of God's ever doing anything unloving. Because most Christians fixate on the "God is love" message of the New Testament, they often forget the foundational Hebrew scriptures that paint what may actually be a more realistic and less one-sided picture of the divine.
As a matter of anthropology, I tend to think that we instinctively recognize the dynamic balance of forces in nature. Throughout history, Christians couldn't seriously deal with the implications of a totally all-conquering God whose goodness washes all evil away forever and ever. Yes, such language appears in our liturgies, but it's a curious historical fact that the role of Satan/cosmic evil gained prominence over time, such that Christianity has, even today, most or all the characteristics of the ethical dualism found in such systems as Manichaeism or Zoroastrianism. We instinctively know that every yang has its yin; the image of an all-good, unambivalent God runs against the grain of our instincts, and we find it suspect. So we pump Satan up and make him as big as God.
We should still talk about this, but as you well know, theodicy's been around since forever, and no talk, no matter how long, will ever really settle the question; that's pretty much a matter of faith.
[NB: When this email was written, only a few days after 9/11, we still didn't have a clear notion of the body count. I think what I wrote was "5000 people," which is obviously incorrect. I've edited the letter to reflect, retroactively, what we now know about the death toll from that day, and use the generic "thousands of people" to express the same sentiment. ]