see sig for my laptops. The macbook I use 99% of the time but i take the iBook with me whenever I think that the macbook might be stolen. The ibook will soon be either given to my mom (depending on her new job) or sold.
I have a MBP 15,4 2,16 that is "portable" and a MacBook Black that is "very portable". In reality I use maily the Pro, the MB is just as I move in my house, from sitting room to the bathroom and/or to the garden