Choosing the right computer for you - part 3 - Ergonomics
When it comes right down to it, you interact with your computer through the keyboard, mouse and screen.
Screen size
For laptops, screen size is an important issue because it usually affects the overall weight of the unit as well. Smaller screen size usually means lighter weight and better mobility. Larger screen size means you can fit more on the screen. Balancing these two issues is a personal thing, and will depend on how much "mobile" use the laptop will get.