I've been hanging around Macrumors for a couple weeks and have spent most of my time trying to decide if it's worth it to buy the Macpro now or wait and it seems it's not really worth it for me to wait. qIt doesn't seem like quad-core prices will drop that significantly when and if 8-cores come out.... and it's not worth waiting a couple or a few months for......same thing with the idea of waiting for Leopard. I could get the upgrade if I want later on. See, right now I am going crazy with my Dell Dimension xps from 2000 or whenever. I'm really anxious to start my digital home studio and the few months of potential waiting and money saved just don't seem worth it. Anyway, that aside, I'm still confused on RAM upgrade configurtions. I'll be getting a 2.66ghz 1(2x512mb) RAM and I want to upgrade, buying from other sources, to at least 1gb more, so I need to to know, what is the best way to config.? (2x512mb) vs (1x1gb), or (4x512mb) vs (2x1gb) and which slots? Today the recommended RAM sites had these prices and selections: Crucial: 512mbx2 $157, 1GBx2 $293 OWC: 512mbX2 $174, 512mbX4 $349, 1GBx2 $249 DMS: 512MBx2 $198, 512MB x4 $396 I willing to upgrade to either 2 or 3GB at this point so a recommendation on the best route would be very helpful. Also, what's with OWC's Apple certified vs. Apple qualified rating for the RAM they sell? Thanks alot you all. This site has been very helpful to me in making my decisions to buy my first Mac.