I ordered 15inch PB Alu G4 1.33 gz, 256 mb .... last week and getting it on Monday. I am a life time windows user switching to Mac. This is my first mac and my use will be basic (i.e. heavy office use, internet, email etc). I won't be doing any graphics or games so thought 512 mb ram would be enough. Yesterday I bought 256 mb on ebay to add on. The ram I bought came out of Alu PB G4 1.25 gz (different processor speed than mine) as the owner is upgrading ram on his PB. The ram chip is made by Hynix and the specs for the ram chip are PC2700S-25330 256MB DDR 333MHz CL2.5 . I checked the Hynix web site for the details and it seems compatable with the PB (1.33 gz) that I am getting. Does anyone know if I will be able to use the ram chip that came out of PB with 1.25 gz processor in to PB 1.33 gz processor(every thing else is same in both PBs). And if I try it will I be causing any damage to my PB?