High-tech travel planning.

Just when you thought you had discovered every possible use for your computer, a new one pops up-travel planning.

Want to go skiing? Spelunking? Biking in Europe? Or how about a nice wine-tasting train ride? Your computer can tell you where, when, and how much it will cost. You can even make your reservation with a few strokes on the keyboard.

Computers do lots of t' well, but they're absolutely best at storing, retrieving, and categorizing huge amounts of data. Recently, several entrepreneurs have used the electronic brains to collect mountains of material about recreation, and the result is a series of databases brimming with information on leisure travel. Think of them as huge electronic Rolodexes.

You can tap into this cornucopia in several ways. First, you can ask your travel agent to poke around in database for you, but that wouldn't be nearly as efficient-or as much fun -as doing it yourself. Or you can subscribe to one of the services that puts its information on disks; pop a disk into your computer, and you can browse to your heart's delight.

However, the most exciting way to explore a computerized travel database is to do it on-line.

You can call up information as detailed as the description of an individual guest ranch and even the Computers can help you plan our next vacation whether your interest is an exotic safari or a wilderness voyage or something more traditional like a golf, fishing, skiing, or bicycling vacation. Serving as your own travel agent gives you the browse to brows dream-to your heart's content at the same time as you determine your dream vacation's cost and even make reservations.

Here's how it works: In some distant, temperature-controlled room, a mainframe computer crammed with information hums away 24 hours a day. Using a modem and communications software, you connect your computer to the big one by phone. Following on-screen instructions and menus, you call up information on the places and activities that interest you. When you find valuable material-perhaps the description of a guest ranch or maybe a list of campground facilities or a bicycling tour package-you save that data to a disk in your computer for perusal later. If you like, make reservations or request additional material. When you finish, you sign off.

Naturally, this isn't free. Most travel databases are available through one or more of the major computer networks-such Compuserve, Prodigy Delphi, or GEnie. Typically, subscribing to a network costs from $25 to $50 and per-minute online costs range from six cents to 40 cents, depending on the speed of your modem, time of day, and other factors. Usually, the phone call itself is free. Keep in mind, however, that subscribing to a network also buys you access to a cornucopia of other computerized services. The Official Recreation Guide, mentioned below, is something of an exception, since it is available via networks and as a separate entity. One travel planner, the INFO Ski Network, is free to consumers, including the phone call in many cities.

The following is a rundown of the suppliers of computerized recreational travel information. All on-line services update their information daily, and disk services are updated annually.

*The Official Airline Guide is a compendium of plane schedules that allows you to browse the myriad possibilities and make your own reservations. OAG is available through most major computer networks.

* Eaasy Sabre, a product of American Airlines, also provides airline schedules and can be found on most networks.

* The Boston-based INFO Ski Network provides an avalanche of information about more than 500 ski areas in several countries. Typically, the entry for each resort includes ticket prices, the number and type of lifts, slope difficulty ratings, upcoming events, and information about such essentials as lodging and dining. Because the INFO Ski Network charges resorts a fee to be listed in the database, it provides the information free to consumers. A stripped-down version of the database is available on disk for folks without a modem. For more information, call 617/262-2860.

*World-File, another ski directory, is available only on disk. In addition to the necessary information about lifts, slopes, prices, and accommodations, this database contains first-hand reports compiled by top ski writers. With this directory, a user can enter preferences for dates, costs, slope difficulty, and other factors, then let the computer select those resorts that fill the bill. The North American disk covers more than 450 resorts and a calendar of 1,000 events. The international disk offers data on the best skiing in Europe, Russia, Japan, and elsewhere. Each disk sells for $24.95. There's also one on cross-country skiing for $14.95. Call 800/624-5659.

* Adventure Atlas, based in Del Mar, California, contains information on 14,000 different recreational tours, ranging from French wine-tasting trips via bicycle to honeymoon safaris in Kenya. Tour themes include fall foliage, opera, whitewater rafting, hutto-hut European hiking, archaeological digs, whale watching, and nearly 100 other vacations. A typical database entry includes the location, tour provider, information about meals and lodging, dates, special equipment needed, immunization requirements, and a brief description of what to expect. Searches can be done by trip category, by tour provider, or by geographic region. Call 619/481-7337.

The Official Recreation Guide, housed in an unassuming office building in Whitefish, Montana, is the largest leisure travel directory in the world. Its tens of thousands of entries cover every conceivable kind of recreation-yachting, hot-air ballooning, camping, golfing, fishing, bed-and-breakfast places, dogsledding, wind surfing, and many more.

The ORG contains two types of items. Its "white pages' provide essential-but somewhat limited-information about a host of public and commercial recreational facilities and services. For example, this listing can tell you how many campgrounds exist in Yellowstone National Park, how long you can stay, whether water is available, and so on. The "yellow pages" entries are different. These electronic brochures offer as much information as the travel provider-a resort, hotel, guide, etc.wishes to pay for. A rafting outfitter, for example, may even mention that his riverside menu includes wholegrain breads, crab-stuffed chicken, and dutch-oven cobblers. It's not unusual for an entry to run dozens of pages.

If you've already selected a destination, the ORG can tell you what to do and see there. It can also list instantly all the locations nationwide (and beyond) offering trail rides-or helicopter flights or scuba diving or whatever. And if you want to know where flyfishing and mountain-biking opportunities exist in the same locale, it can tell you that as well. Also included are lists of packaged tours, last-minute bargains, upcoming events in virtually every major city. In many cases, you can make a reservation while on-line.

The ORG is available through several networks and by direct phone connection (toll-free from 350 cities) for an annual fee of $29 plus 15 cents per minute of connect time. For information, call 800/826-2135.

Truly, the computer has become a travel assistant of the first order. About the only thing it won't do is pack your bags-but the way things are going, that may be next. AF