I'm looking to purchase a used MacBook off of Craigslist so I can get to Lion/Mountain Lion. I've seen some that come with Lion preloaded or that have Snow Leopard. Usually I would wipe the drive or maybe even put my own drive in it, but I was wondering if I can use their install of SL, sign onto the MAS, then download Lion and move that to a USB drive. This would save me the steps of wiping their HDD, installing my SL, updating, downloading Lion, and installing Lion. I have a Core Duo MacBook so I don't think I can download Lion onto it since I know I can't install it.