Background: I am a doctor. I am very important. I have many leather-bound books and my 2 bedroom rental apartment smells of rich mahogany. I am a pretty big deal.............well..........not really. I am a resident in radiology and I need help buying a new macbook. I currently have a G4 15" powerbook that is ready to be replaced. Can the single 9400M graphics card in the 13" or 15" handle the large image files (MRI and CTs) that I will be dealing with? These files are big, usually in excess of 1gig each. Sometimes up to 8 gigs each (they contain 1000s of hi-res images in each file. Really big. Would upgrading to the dual graphics card make a difference? What about once snow leopard comes into play? This computer won't be my main base, but I will need the ability to work with these images on my laptop and also to incorporate them into keynote/ppt presentations. Thanks for any help.