I am getting a MBP in mid-june, and have been doing my homework. I do a lot of video editing and Photoshoping so I think it would be smart for me to get the 2GB of RAM option if it wasn't about $220 over what it should be, so I will be ordering it from some third party site. Heres my question: I have never needed to add or replace RAM before, so this may seem stupid. When adding more RAM, are you simply adding it into the slot, or removing the current RAM and replacing it? In other words, the 2GB that comes with it are removed and replaced by the 2x2GB? Also, is there any real difference between the pre-installed version and third party RAM? Thanks.