I have a 15" MacBook Pro 2.16 GHz that I purchased in May 2006. It has two memory slots, with 1 GB in each slot right now, adding up to 2 GB RAM. I am wondering if it is possible to put in 2 2GB sticks instead and have 4 GB RAM? I realize that it may actually only be useable at around 3.3 GB, but that still provides more memory than the current 2 GB. I did run a search to try and find the answer already but only found inconclusive answers way back in 2006 around the time the machine was newly available. I hope someone has a definitive answer now, as I have a potential purchaser who wants to buy my machine if it can be upgraded. Thanks!