I bought my 13" Macbook Pro back in July. Did the "upgrade" to Snow Leopard for $9.99 or whatever it was. Am now running SL and like it a lot. That SL Disk says "Mac OSX Snow Leopard Upgrade DVD". My question is can I install this disk on my Mac Mini running Leopard or is the "special upgrade disk" something completely different? This isn't a moral question I'm asking for technical advice. Has anyone used their "upgrade disk" to upgrade any of their other macs in their household? Thanks guys.