Ok so I'm going to be getting my 15" MBP soon and I'm thinking about buying the mdp to vga adapter (or possibly dvi). I was wondering if I have my mac hooked up to another monitor, do I still need to have the actual computer open? Can I just hook a keyboard and mouse up to it and close the laptop and just use the external monitor? The reason I ask is because my brother has a white macbook that he hooks up to his TV via HDMI. He said he has to keep his open while watching movies etc or it just goes to sleep. He doesn't use the apple brand cable, this wouldn't seem to make a difference though. Any advice on what it will be like? Will I need to have my laptop open if I hook it up to my computer monitor or tv? Thanks.