Use the following guidelines when choosing a keyboard:
The position of the primary alphanumeric keys is standard on all keyboards other than those that use the oddball Dvorak layout. What varies, sometimes dramatically, is the placement, size, and shape of other keys, such as the shift keys (Shift, Ctrl, and Alt), the function keys (which may be arrayed across the top, down the left side, or both), and the cursor control and numeric keypad keys. If you are used to a particular layout, purchasing a keyboard with a similar layout makes it much easier to adapt to the new keyboard.
Keyboards vary both in obvious ways?layout, size, and form?and in subtle ways?key spacing, angle, dishing, travel, pressure required, and tactile feedback. People's sensitivity to these differences varies. Some are keyboard agnostics who can sit down in front of a new keyboard and, regardless of layout or tactile response, be up to speed in a few minutes. Others have strong preferences about layout and feel. If you've never met a keyboard you didn't like, you can disregard these issues and choose a keyboard based on other factors. If love and hate are words you apply to keyboards, use an identical keyboard for at least an hour before you buy one for yourself.
Some keyboards provide dedicated and/or programmable function keys to automate such things as firing up your browser or email client or to allow you to define custom macros that can be invoked with a single keystroke. These functions are typically not built into the keyboard itself, but require loading a driver. To take advantage of these functions, make sure a driver is available for the OS you use.
Although it sounds trivial, the weight of a keyboard can be a significant issue for some people. The lightest keyboard we've seen weighed just over 1 lb., and the heaviest was nearly 8 lbs. If your keyboard stays on your desktop, a heavy keyboard is less likely to slide around. Conversely, a very heavy keyboard may be uncomfortable for someone who works with the keyboard in his lap.
Keyboards are low-margin products. As a means to differentiate their products and increase margins, some manufacturers produce keyboards with speakers, scanners, and other entirely unrelated functions built in. These functions are often clumsy to use, are fragile, and have limited features. If you want speakers or a scanner, buy speakers or a scanner. Don't get a keyboard with them built in.
Various manufacturers make wireless keyboards, which are ideal for presentations and TV-based web browsing. Wireless keyboards include a separate receiver module that connects to a USB port or the PS/2 keyboard port on the PC. The keyboard and receiver communicate using either radio frequency (RF) or infrared (IR). IR keyboards require direct line-of-sight between the keyboard and receiver, while RF keyboards do not. Most IR keyboards and many RF keyboards provide very limited range?as little as 5 feet or so? which limits their utility to working around a desk without cables tangling. Some RF keyboards and a few IR keyboards use higher power to provide longer range, up to 50 feet or more. These are often quite expensive and provide relatively short battery life. Whichever type of wireless keyboard you get, make sure it uses standard (AA/AAA/9V) alkaline or NiMH batteries rather than a proprietary NiCd battery pack, which is subject to the infamous NiCd memory effect whereby NiCd batteries soon begin to lose the ability to hold a charge.