Five years of Apple: 2005 iBook to 2010 MacBook Air
The incredible shrinking 'book
Other components of the 2005 iBook that contributed to its thickness have also been slimmed down or eliminated, including its optical drive (which has had its usefulness erased through a series of measures, from wireless Disc Sharing to solid state reinstall media to digital media downloads and cloud storage, and in the near future, software downloads through the Mac App Store), its hard drive mechanism (eliminated on the Air in favor of solid state storage), and a variety of electronics that have have been replaced by fewer integrated chips.
Apple's integrated batteries also eliminated the need for space hogging battery pack housing and release mechanisms.
Learning from iOS devices
Apple has also brought inventions from its iOS product line into MacBook designs, including support for iPhone-style headphones with an integrated mic and remote controls. Display construction technologies related to the iPhone and iPad allow the new MacBook Air screen lid to be extremely thin, reducing the girth of the hinge and making the physical catch release button of the iBook unnecessary.
Like all recent MacBook models, the latest MacBook Air models use the integrated batteries that critics originally assailed as limiting; that integrated design has enabled the entire line of MacBooks to set new records in battery life while also delivering long life battery performance that requires fewer dead batteries to end up in landfills.
While greatly improving the conventional notebook across the last five years, Apple has also replaced it in many applications with the even more mobile iPad, which costs half as much as lasts twice as long on a battery charge.
The pace of Apple's technological progress over last five years is particularly impressive when compared to the previous five year period from 2000-2005. This suggests the potential for even faster development in the future, as Apple shares more technologies between the Mac and iPod and iOS devices and as the volume of computers Apple ships continues to grow.