I just bought my friends 2007 MacBook from him and had it restored (out of the box set-up),running Snow Leopard. This is my first Mac, and I love it. However, the hard drive is only about 80 gb and I would like to buy an external hard drive. I looked under the "About This Mac" to try and figure out which USB it has, but I'm not sure. I think it is 1.10. I know nothing about the differences between USB 2.0 and 3.0, so I'm not sure what kind of hard drive to pick up. What do you recommend?