Okay, so I'm planning to buy a MBP after WWDC and to configure it with the base 512x1 RAM. Now, I wanted to buy a 1GB stick from Crucial as soon as I buy the MBP, then possibly get another 1GB down the road. Originally I planned to just take the stock 512 out and put the 1GB in its place for fear of memory-mismatching issues slowing the computer down. However, I'm beginning to wonder if it would be benificial instead to keep the 512 in to make it 1.5GB. Would the memory increase of .5GB outweigh the disadvantage of memory mismatching, or should I just swap the 512 for the 1GB?