QHow do you evaluate

LCD screens?

ALiquid-crystal displays can be tricky to evaluate. In general, you should look for contrast ratios from 350:1 to 500:1, a brightness of 250 "nits" or higher (yes, that's a real measurement), and, if you're into any sort of fast-paced gaming, a response time under 25 milliseconds. A monitor with both VGA and digital (DVI) connections will offer the most compatibility with future desktops and laptops.

But the most useful tools to judge a monitor are your own eyes. One reader, a professional photographer, took this practice to one extreme: He loaded up a laptop computer with his own photos, took that to the store and plugged it into three LCD monitors to see how well each displayed the pictures.

You don't need to go that far, but the basic principle still applies: Let your eyes decide. Please remember, too, that LCDs can have dead pixels out of the box, and if yours has more than a handful you should be able to get it replaced.

I saw someone using a wireless connection in a coffee shop that wasn't WiFi. It was some Verizon service -- what was it?

Wireless computing, already a confusing subject, is about to get more complicated. Verizon Wireless recently introduced the broadband service this reader saw, which runs as fast as WiFi but over a much broader area. It costs more than WiFi, however, and can't be used to network your home computers.

Verizon's BroadbandAccess Ev-DO ("Evolution Data Only") service costs $80 a month and, for now, works only in the Washington and San Diego areas. But it's fast and it works. And it's going to have company. Nextel is testing a wireless-broadband service, and other companies -- for instance, a start-up called Clearwire Inc., founded by cellular entrepreneur Craig McCaw -- plan similar offerings.

-- John Gilroy

John Gilroy of Item Inc. is heard on WAMU's "The Computer Guys" at noon on the first Tuesday of the month. Send your questions to him in care of The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or via e-mail to jgilroy@iteminc.com.