theres already a ton of threads on this, but whatever...
For the macbook- yes, because there have been so many problems with them.
For the ipods- it depends, i recently asked the same question about applecare for my nano, and someone said that since it uses flash memory, it was very hard to break. For any other ipod (video, shuffle) i would base it on your budget. Its only like $60, so if you can afford it and want some peace of mind for an extra year, then go for it 😎