Whether on the beach at Waikiki or on the desktop, thin is in. Flat-panel displays are more affordable than ever, but is an LCD the best display for you? And if so, what features should you shop for?

The most obvious benefits of LCDs over CRTs are size and weight: A 15-inch LCD weighs less than 10 pounds, while a typical 17-inch CRT monitor (whose viewable screen area approximates that of a 15-inch LCD) tips the scales at about 40 pounds.

LCDs generally show brighter images than CRTs, and their brightness doesn't dim as quickly with age. Likewise, LCDs usually have better contrast--the difference between the brightest and darkest parts of an image on the screen. And the flat panel's high brightness means that reflections from room lights or the sun are less of a bother than with a CRT.

An LCD can reduce your utility bill, too. A 15-inch model typically uses 30 watts of power, while a standard 17-inch CRT unit consumes two or even three times that amount. If you run your CRT monitor 24/7 and pay 15 cents per kilowatt-hour, an LCD could save you around $60 a year.

But what about the disadvantages of flat panels? LCDs can't match CRTs for displaying fast-motion video and animation. The pixels on a CRT are tiny phosphorescent dots that illuminate instantly when struck by an electron beam. The slow rotation of an LCD's crystals in liquid can cause fast-changing images to blur.

High-end LCDs handle demanding graphics much better than budget units do. Most PC users will not be bothered by the jittery animation of a slow LCD, but hard-core 3D gamers will need a more expensive LCD or a conventional CRT.

Screen resolution is another drawback: LCDs work best at a single resolution. Setting a unit designed for 1024 by 768 to either 1280 by 1024 or 800 by 600 produces indistinct lines, unreadable text, and blurry edges. Web developers and others who frequently change their screen resolution may want to stick with a CRT.

Flat Facts

Flat-panel displays accept an analog signal, a digital signal, or both. Digital signals produce better graphics, but they require a graphics card that provides digital output. Since CRT monitors use analog signals, most graphics cards offer only analog output. High-end graphics cards sometimes supply both types, however.

To get the best possible graphics, you may need to upgrade your graphics card. And if you do, make sure your motherboard has an AGP slot to accept the new card. (Many budget systems have integrated AGP chips but no AGP expansion slot, so their graphics can't be upgraded.)

Your graphics card must have connectors that are compatible with your LCD. Some flat-panel displays come with standard VGA connectors like those found on a CRT, but many others use the new DVI connectors, which are available in three types: DVI-A, for analog only; DVI-D, for digital only; and DVI-I, for integrated, which is both analog and digital. PC users will typically see only DVI-I, though some people might connect their plasma TVs with one of the other digital connectors (see FIGURE 1).

Before spending your money, give your candidates the eyeball test. There's simply no substitute for looking at images on an LCD. And don't make the mistake of relying solely on specifications. For example, a high contrast ratio generally translates to a higher-quality image. A ratio of 200:1 is considered the minimum for an LCD, and a ratio over 400:1 is high-end. PC World Test Center research shows, however, that vendor's contrast-ratio claims can't always be trusted. See "LCD Specs: Useless?" for the whole story.