It's my birthday in a few weeks and my parents have been kind enough to let me have a MacBook. The thing I'm wondering the most about is what kind of configuration would make it more usable for longer? Yes I will most likely be ordering online. Leaving hard-drive sizes out of the equation and for longevity's sake, should I buy a MacBook with the standard configuration for the 2.4 GHz model with 2GB of memory and a 250GB drive, or should I have a custom-built 2.0 GHz model with 4GB of memory and a 250GB drive? I know the custom configuration is cheaper, but with a slower processor and doulbe the memory, could it cope better with future OS's and apps?