Screen resolution is one of the most important usability factors for a notebook, but manufacturers sometimes skimp on this to keep the cost down. We like screens that are over 800 pixels tall, although clearly trade-offs must be made with netbooks and ultraportables. We also prefer 'wide-screen' resolutions (wider than the 'standard' 4:3 aspect ratio) that allow you to open two document windows side by side. If high resolution is a top priority, look for 15.4in. displays or bigger with resolutions of 1,440 by 900 (WXGA+), 1,680 by 1,050 (WSXGA+, pictured above) or even 1,920 by 1,200 (WUXGA)
Ambient light sensors
The screen consumes the most power of any notebook component, so the bigger and brighter the screen, the quicker the battery runs down. Although you can use power management software to set a lower screen brightness level when running on battery power, we like an idea seen most recently in Dell's Latitude E6500 (pictured), which borrows a trick from the mobile phone world: an ambient light sensor automatically sets the screen brightness to an appropriate level for your surroundings.
Another idea from the Latitude E6500 we like, which is also found in some Apple MacBooks, is keyboard backlighting. On the Latitude E6500 this can be turned on and off manually or set to automatically adjust as ambient lighting conditions change. A backlit keyboard makes it much easier to work in duller conditions.
Flexible power management
For mobile professionals, battery life is vital, and what we particularly value is flexibility over power management. We like notebooks that ship with a second battery, for example — either as a replacement for the main battery when it runs out, or as an adjunct to the main battery sitting in a modular bay. We also like our batteries to have a built-in LED gauge so we can check the charge level without needing to power up the notebook. And the more ways of conserving or extending battery life there are, the better. Many manufacturers provide power management software with their notebooks that goes beyond the basic Windows offering, allowing you to selectively disable system components in order to conserve battery power." (Continued via ZDNet.co.uk) [Usability Resources]