Washington, in case you just arrived from Mars, is a town that thrives on information. Almost everybody here seems to be shuffling gigabytes of data for God, country and business. And each of us has our own means of personal data storage. Maybe your data base is like mine: a rat's nest of paper scraps, Post-it notes stuck to the refrigerator and hieroglyphics scrawled on cocktail napkins haphazardly stuffed into my sock drawer.

Yes, I've got to get organized, so I've been investigating an electronic pathway -- the new generation of pocket- and purse-size computers. Now, promise the manufacturers, I can store all my phone numbers, memos and schedules in one neat, electronic package.

One of the smallest and simplest of these computers is the Calling Card, a $35 "electronic little black book" made in Hong Kong by International Telesis Inc. The size of a credit card and as thick as three cards stacked together, this diminutive gadget has a 2K memory (2,024 characters), which means it holds up to an average of 150 names and numbers. You can also use it as a calculator and enter short memos and any combination of names, numbers, addresses or messages in any order on the 24-character display screen. The card automatically sorts everything into alphabetical order.

The Calling Card has a colorful membrane keyboard that clicks electronically every time you key in data, an automatic shut-off and a three-year battery life. You can even impress yourself with your own importance by entering a three-digit security code. Of course, if you forget the code you'll have to destroy all the data (by removing the batteries) to unlock the display. But hey, if you can't remember three numbers in sequence maybe you're not such a hotshot after all.

International Telesis says the Calling Card lets you "have your most important files with you . . . a full telephone address book and memos too." But I'm still not convinced I want to trade in my scraps of paper for a microgizmo. The Calling Card is a well-designed novelty, but it has shortcomings that underline the risks of trading paper for electronic storage.

First, even though it's the size of a credit card, you can't stuff it into your wallet or back pocket. Bending it will trash the delicate circuitry or break the liquid-crystal display screen. Second, it's much less versatile than even a small address book into which you can quickly jot names, numbers and marginal notes. You can't jot anything into the Calling Card: Each entry must be laboriously keyed in one letter or number at a time by carefully pressing the tiny keyboard. I recommend this as a nice time- consuming hobby involving no heavy lifting.

But perhaps I'm being a technocrank. Maybe the problem is merely one of sophistication. So I also played with Casio's SF-30008K, a beefed-up "Digital Diary." At $100 it's more versatile than the Calling Card but also more complex, accompanied by a 64-page instruction book. Powered by four lithium batteries, this "integrated business tool" holds (with add-on expansion modules) more than 16K. And though it won't fit in your wallet (it measures 5-by-2 1/2 inches and is more than a half-inch thick) the fold-up hard case will protect it from getting bent out of shape.

The Casio has some impressive powers given its petite size. It's a calculator, of course, but it also stores names, phone numbers and key words in the telephone file and has a second file for brief memos, timetables and lists. A third file contains schedules and calendars. You can, says Casio, schedule appointments according to the year, month, day and time. The built-in calendars run from January 1901 to December 2099, so you can input data backward and forward over a 200-year range. (I'd love to do lunch, darling, but my data base says I'm booked solid for the next 12 years.)

Like the Calling Card, the SF-30008K automatically finds initials or names. Its password function lets you create a secret word up to 47 characters long. But again, you'll have to zap data and start all over again if your memory fails. (Fortunately, I've never forgotten the password to my sock drawer.)

Though the SF-30008K has an attractive membrane keyboard, Casio designers have inexplicably laid out the letters like a standard typewriter keyboard. A strange choice because there's no way you can touch-type on a keyboard this tiny unless you're an elf -- in which case you probably have magical powers that surpass those of midget computers.

Casio, Sharp, Selectronics and other manufacturers are already building similar data storage capabilities into wristwatches and larger electronic notebooks. All of these gadgets are certainly more interesting to play with than mere pen and paper -- but are they really an improvement? I love electronic toys, but I'm not sure owning a digital daybook will automatically solve my organizational ineptitude.

There's also the problem of acts of God -- like fire, floods and having a toddler plop your data base in the toilet. Which means everything you enter into these devices must be carefully and religiously backed up by written records. Ah, but if you could keep records so well organized, you probably wouldn't need a pocket computer in the first place, would you? ::