I might be trading a 1.43 14' iBook for a 1.83 MacBook. The Macbook has 9 months on the applecare left. I'll be trading locally, and before I trade I'll be able to look the machine over for problems. What should I look for? Any benchmark programs that would alert me to any hardware issues? Any programs that are known to make a macbook turn into the moobook when the fans kick in? What else should I beware of? Thanks for the advice.