I know there are a lot of threads about ram floating around, but i couldn't find an answer to this specific question.... I just bought 4 gbs of ram for my AL iMac 24"...and so I have an extra 1 gb stick that came out of the iMac.... I also have a white macbook....I can't remember the specs exactly on it....it was the first generation macbook...I believe it's a core duo 2.0... When I bought the macbook I had them put a gig of ram in it (2x512)... my question is, can I take one 512 stick out of the macbook and replace it with this 1 gig stick for a total of 1.5gb?? I know a small increase of 512 won't be hardly noticeable but hey, I have the stick so I may as well use it..... both machines use the same memory right? thanks for your help! ps. if it does work does it matter which slot has the larger stick?