I agree with .sarah. I just finished a digital beginner's photography class, and the teacher swears by Canons. I have the rebel xt, and I love it. I'm getting my third lens for Christmas. I have only Canon brand lenses so that makes a difference too I think. I also don't hear much about Olympus. The bid debate is Canon or Nikon, so I would think they're better cameras. If you can get the Xti, go for it. It's got more mp than the Xt (which is why you were leaning toward the Olympus, right?).

Oh, and CANON!!