(FORTUNE Magazine) – THE WORLD'S SMALLEST FAX Compact enough to be slated for inclusion in an upcoming edition of the Guinness Book of Records, Ricoh Corp.'s PF-1 facsimile machine measures 11 by 7 inches -- it fits on a sheet of typing paper -- and weighs just 5.5 pounds. Ricoh may have skimped on size, but not on features: The PF-1 holds enough paper for 30 letter-size pages, prints out faxes at high or low resolution, and has error correction circuitry that keeps garbles caused by phone-line static to a minimum. The PF-1 even serves as a portable copier. It can transmit and receive via the cellular phone in your car, drawing on batteries or current from the cigarette lighter. Once you're indoors, the PF-1 plugs into a regular AC outlet and telephone line. Price: $1,695 at electronics and office-product stores across the U.S.

CAR-FRIENDLY CASSETTES When you leave audio cassettes on your car's dashboard, the hot sun can turn ! your favorite Bonnie Raitt tape to butter in no time. The UX Turbo cassette, by Sony Magnetic Products Group of America, is designed to take the heat. Sony has fortified the shell, protective case, window, and hubs to withstand temperatures of up to 240 degrees. Even the glue that holds the label has been reformulated to remain intact in a frying sedan. The tape itself is a high- grade type that has always been able to tolerate heat. UX Turbo cassettes will go on sale in April in car stereo dealerships and record stores, with 60-, 90-, and 100-minute versions priced at $2.99, $3.99 and $4.99 respectively.

WEIGHT WATCHERS LITE The big mama of guilt-free frozen foods is going on a diet. Up to now, the secret of Weight Watchers has been to serve small portions: Ounce for ounce, according to Consumer Reports, its entrees are typically just as fattening as ordinary frozen food. But beginning this month, many Weight Watchers' entrees, breakfasts, and desserts will contain 14% less fat, 20% less sodium, and 19% less cholesterol, on average, than previous recipes. (The portions will still be small.) A subsidiary of H.J. Heinz of Pittsburgh, Weight Watchers Frozen Foods has replaced ingredients such as cheese made from whole milk with low- calorie substitutes.

VIDEOCONFERENCING GETS CHEAPER Have the threat of terrorism and rising airline costs put a crimp in your business? How about holding meetings via TV? PictureTel Corp. of Peabody, Massachusetts, has developed videoconferencing gear that sells for around $40,000. That's half the price of comparable systems. The Model 200 shown is meant for offices and small conference rooms for up to six people. Its electronics box, monitor, camera, and sleek key pad can be arranged in any way that suits the space, much like the pieces of a stereo. To control the camera, volume, and other functions just use the key pad to select from on-screen menus. A ''windowing'' feature lets you see yourself as you appear to colleagues on the other end of the line. Meanwhile special audio circuitry accommodates the starts, stops, and interruptions of normal conversation -- even those moments when everyone seems to be talking at once. Says Al Lill, a program director at the Gartner Group, a Stamford, Connecticut, research firm: ''PictureTel's system proves that videoconferencing is becoming as practical as desktop computing.''