ok..been searching for this...cant find it ... Say i order a macbook with 1GB .... I want 2GB I Will go through crucial.com or whatever it is called...but wHat do I buy?? 2 of the 1GBs to fill the two slots in my macbook? What does the macbook come with? Just 1 slot filled with 1GB? or 2 slots filled with 516 mb or something close? Basically what do i need to buy from crucial to get 2GB. a 1GB to go with my exisiting macbook memory or a complete new 2GB?