Hi, I have the Late 2008 uMBP with 2.4GHz, 2GB DDR3 RAM, and 5400 RPM HDD. I'm looking to upgrade the RAM as it seems 2GB just isn't cutting it for me these days. I run a lot of apps at once--Safari with 4-6 tabs, Excel, Word, Mail, iChat, and iTunes. Sometimes MATLAB or Eclipse Java IDE or Xcode is running too. I was wondering if i should get a pair of matched 2GB sticks or one 4GB stick +1GB that is already in my mac. I know unmatched pairs aren't ideal, but is the performance really affected THAT much? I presume I really wont be needing more than 4GB at this time (for the above mentioned tasks), so I guess 4GB does fill my needs now, but 5GB is always good too, lol. Any thoughts? Thanks!