Honest opinions here please - i'm a normal user - don't really use my ibook for any professional apps, mainly office, internet, im, music, dvds sometimes. I do, however appreciate the speed increases associated with more ram. My question is what kind of difference will I notice between the 512 mb upgrade and the 1gb upgrade? Will I notice much difference? Is the 1GB worth the more than double cost of the 512 upgrade? I'm a student on a tight budget. Opinions, please.