it depends on a few factors i think-
If you just use the laptop around the house, don't move it around to much, and are careful with it, you might not want to bother with applecare. If you don't plan on keeping hte computer - that is you plan on upgrading within a year or two, then it might not be worth it. Remember - applecare is $250 - that's almost 1/4 of the price you pay for the computer.
Otherwise, if you plan on putting some hardcore miles on the laptop and you will be on it a lot, then it's worth it to get applecare. A lot of things can break on a laptop from just general wear. The latch, the keyboard, battery, screen hinge, speakers.
Remember is that if you're taking your laptop all over there's a decent chance of you losing it or having it stolen, or you doing some accidental damage to it. If this happens then applecare is not gonna be worth a thing to you and you will be out the entire cost of the computer, plus the applecare... it's not like you can repalce the macbook and then transfer your applecare over.
Two or three years down the line, if you do have a major problem with your computer and you don't have applecare, your macbook will probably not be worth much more than the $250 you invested in applecare. 3 year old iBooks go for around $400 and that's only because the PowerPC chips have made so little progress, especially laptop chips, in the last few years. It is likely that your macbook will be worth around $300. THis means that if it were to break you could just buy a working used one for a bit more htan the cost of applecare. selling your broken macbook for parts should at least recoup you that difference.
Finally you do get a full year of phone support instead of 90 days. If you are gonna need phone support - if you aren't too tech saavy, then you may want this.
From personal experience, I've owned 3 ibooks since 2000. I never had applecare and there was only one time I wish I had it. The case covering on my key lime iBook's dvd drive fell off and the connection to the power supply stopped working about 3 years in. Another iBook I cracked the screen by dropping it - applecare wouldn't ahve done me any good. That same iBook had logic board problems well after the warranty was up, but since apple had acknowledged it as a problem in their manufacturing, they repaired it for free.
So yeah, I'm not a big fan of applecare for myself, but it is definitely worth it for people in certain situations.
