I am wondering if I really need more than 1gb of ram. Should I buy a 500mb stick or a 1gb for a total of 1.5? New to the mac plus I am at work now on my work PC. Will activity monitor show how much ram I "would" use? Maybe someone who has 1GB can let me know if they are using all 1gb (i.e maxed out) for quicken and/or MS office?