warranty
it's probably worth it to put down a clarification on the apple warranty...
with your new computer (or a refurb), you get one year of hardware coverage and 90 days of phone support. this means within the first 90 days, you can call apple customer service, free of charge, and ask them any questions you have.
after 90 days, you only have hardware coverage. when you call apple, they will ask for a credit card number to charge you $49 per incident IF and ONLY IF the question you have is NOT hardware related. if the problem you have with your machine is related some software you've installed, then apple will charge you that $49 because diagnosing and solving that kind of problem is not part of the warranty.
apple care basically extends that first 90 day service - "you can ask any question you want for free" - to 3 years.
a lot of people get furious that they are being charged $49 when in fact, apple will only charge if it's not hardware related.
personally, i have rev. A 12" PB i got in feb. and will not be buying applecare. even with edu. discount, it's $285. at that price, with the rapid advancement and price drops of newer machines, i'd rather get a new laptop than fix my "old" one. i sure hope mine doesn't break, but if it does, i'm not sure if i want to spend so much to fix a machine that will be quite "old." i have all my doc's backed up, which is the most precious thing on my computer anyway...