I received my new Macbook Pro (2008) in the mail about a week ago and I've pretty much gotten everything in order. There is still one thing that stumps me, however. On the front of the computer, to the right, there is a rectangular slot (can be seen on Apple's pictures; closed). I'm familiar with most computer slots from ExpressCard to Media Card slots but I can't guess as to what this is. Can anyone tell me?