I'm thinking of buying my first Mac ever pretty soon. I can get an educational discount and also get a free iPod Touch if I buy before September 15. I understand that Snow Leopard will be available "in September" so I will have to receive it separately if I buy my Mac between now and then. So, I've never owned Macs before, so I'm wondering how the upgrade from Leopard -> Snow Leopard will happen. Is it like Windows where you can choose to do a "clean installation" or an "in-place" upgrade? Coming from the Windows world, I tend to lean more towards clean installations.