The extra thickness of the N900 is in the bottom part of the slide that has the keyboard in it. The top parts with the screens are the same thickness on the N97 and N900.

Is the higher performance processor so much bigger to account for a 20% volume difference from the N97? Even though the N97 has a larger battery and a more complex sliding mechanism? There are things that are bigger in the N97 too. To me it just doesn't add up to accounting for a 20% volume difference on the two devices.

It seems to me like people have just decided that the N900 could not possibly have been otherwise. Nokia in its divine and infallible wisdom made the only design they could have possibly made, with the given components, and all things are prefect, because it is the best of all possible worlds.

Don't get me wrong either. I like the N900. I don't care about the thickness as far as handling the device goes. It seems more like a concern for pocketability, since this is after all supposed to be a phone. But I am curious why it's so thick, when other Nokia devices with extremely similar components and some larger components are considerably smaller and thinner. All of the reasons people have offered so far are pretty easy to discount.