Let me start off by saying I don't know much about laptops, but the few questions I've asked on these forms, have given me lot's of good answers. I'm using an old OS 10.4. I own an iPhone 4. When I try to plug the iPhone into my Macbook, iTunes says I need to upgrade. When I download the upgraded iTunes, it says I need to upgrade my computer to 10.5. So... is this the case? Is there anyway to get around upgrading my comp so I can sync my iPhone up with my Macbook? If not, what's the best way to upgrade from a 10.4 to a 10.5 so I can download the new iTunes? Mac Specs: 1.83 GHz 2 GB Suggestions?