hi, i've been looking at macbooks on ebay to replace my trusty and faithful powerbook g4. i've found several macbooks w/ a lot of features i like but the ones in my price range have tiger as the operating system. my g4 has leopard on it so i want to update my new companion to the best it can be. so my question is can i update something from tiger straight to snow leopard and skip leopard. any advice is much appreciated