I currently own an original iMac G5, which I have upgraded to Tiger and iLife 06. I am a dot mac member as well. I intend to buy a black Macbook and was planning to wait for the release of Leopard and iLife 07, as I don't need a laptop immediately. However, one of the intended purposes of buying the macbook is to sync with my iMac to provide a continual backup of my photos and iTunes. (Also, the iMac will have to go into the shop soon to replace a failing power supply.) If I wait for Leopard on the Macbook, will I have to upgrade my iMac to Leopard as well? Is there any advantage to having the same OS version on both machines? Is there any other reason (apart from impatience) to buy the Macbook now? Thanks.