I am about to purchase my new mac and had a somewhat ignorant question. I was wondering if I should power off my mac when I am not using it. Of course my instinct says yes, but at the same time mac has a lot of cool features such as alarms (from iCal for example) which makes me think that leaving the machine on standby is okay. Not to mention when leopard comes out time machine can be set to backup every night at a certain time. So those ideas are making me think it's OK to leave it on. But will this have any effect on how long my computer's life will last. What are the positives/negatives for either way? If anyone can help it will be much appreciated. Thanks!