Just an update:
I've been doing the bleaching trays for a week. It's a 2 week process but after only a week the results are amazing! I've had so many of my friends compliment me. Today when I was at the mall, one of the cashiers said to me, "You have the nicest smile. Your teeth are straight and they're so white!" I was so excited! (sidenote: the bleaching trays will not make your teeth straight
my straight teeth are the result of 2 years in braces...yuck).
My dentist told me (and was later confirmed after reading a bunch of studies) that since the bleaching trays get to the dentin of your teeth, the bleaching can last for 5 years plus.
The only thing that sucks about the trays is that it makes your teeth really sensitive. I accidently got an ice cube while drinking soda today and it was soooo painful. Also, the bleach that is used can irritate your gums. My gums are slightly red for about an hour after wearing the trays (I wear them at night). These side effects will, of course, go away after I stop using the trays.
Overall, I'm completely thrilled with the results. If you happen to have some extra money, definitely do this. It works better than the Crest Whitestrips and the results will last for a lot longer.