Why stuff thick travel guides into your briefcase when, with a series of software programs that covers some 30 U.S. cities, you can simply tote advice in your laptop?

The backdrop of each City-Guide package is a digitized map created by Etak, based in Menlo Park, Calif., a leader in an emerging technology called geographic information systems (GIS). The maps zoom from an overview of a whole city to a window covering a few blocks. On them are overlaid the location and nature of visitor sites (including various corporate headquarters). Clicking on an icon brings up a description of a spot.

Alternatively, checking off desired features (a hotel pool, for example, or a restaurant with a view), brings up establishments that fit price-and-amenities criteria. If CityGuide doesn't like a place, it'll say so; its frank appraisals are extracted from the Zagat Survey, a reliable critic.

CityGuide, by Zagat-Axxis (800-394-3549; $99 per city, three for $249), requires Windows, two megabytes RAM, and at least five megabytes of disk space. -- Robert A. Mamis

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