I have to commute next year and wanted to do my course work on the train. It's a 2 1/2 hr journey each way, and I need to run cs5 on it. I have had so many people making recommendations to me about what laptop I should get, and I am so confused but I am drawn to the macbook because it is so light and I have to carry it around campus with me all day. Following steps such as turning off unnecessary programs, only running one program at a time, dimming the screen... will a mbp last the journey, or at least a significant portion of the journey (and then charging it again for the journey back...)? I don't even know if the answer is out there, but I don't know what computer to get as I don't want to waste all this money on a laptop, to only have it die half an hour into the trip. Only reason I want to get a laptop is to do work instead of sitting around staring out the window on the train, wasting time. (I don't have days off so its important I'm not wasting time.) Also, if I want to get one, what would be the best configuration? Like, 13 or 15, 4gb or 8gb ram? I read a lot about how sometimes the extra ram is worth it because though it's more power to run it, its even less power needed for the hdd. Anyone in a similiar position to me who can give me answer on battery times, and what sort of mbp you have?