I've got a 1.5GHz G4 PowerBook with 2GB RAM. I run use Lightroom but it is seems to chug along and working on my pictures feels more like a chore than a hobby! My father has a 2.16GHz Intel Core 2 Duo MacBook with 2GB RAM and for scientific research I installed Lightroom and imported my full library. I wish I hadn't because now I know how much faster Lightroom is!!!!! I don't know how long I can hold out now before Steve gets a few more of my gold coins in exchange for a 24" iMac!?!?!