Well actually Carbon Fiber, or like the back of the white iphone!! I think their was a mention of apple testing a carbon fiber bottoms in order to lighten the weight by 25% ? What do you think? I think it would be really cool! A true supper light, iphone like device. Truly portable. I would want one just in white! Although I love the aluminum, its still heavy! I don't won't to feel my apple Laptop in my backpack, at all! I would love to see some mockups !