Shopping time again.

Here is a selection of travel gifts, mostly small ones for people on your list who need gadgets. Perhaps need is not the word, but here they are.First choice for this year is a new packable plastic cup, which unfolds, rather than telescoping, and has a small handle so it can be used for hot drinks as well as cold. (It can also accommodate a heating coil.)

On a trip through France last spring, a member of our party had a terrible cold, and it was clearly unwise for her to drink from the communal two-liter water bottle we carried. She was reduced to using the cap from her cough medicine.

Magellan's, Box 5485, Santa Barbara, Calif., 93150-5485; 800-962-4943. Shipping: $2.75.

The biggest worry-saver I have known for those who leave a house in a cold climate for long periods is the Telefreeze. This small plastic cube, connected to the phone line before you leave, reads the temperature inside the house.

If the house temperature drops enough to indicate that the heating plant is not working, the phone, when dialed, gives a busy signal. This is a signal to the owner to call the plumber or the heating company to have the problem dealt with.

The Telefreeze, often available from plumbers or fuel dealers in areas with many second homes or ski cabins, should not cost more than $90.

This item cannot be ordered directly, only through your dealer or plumber. Dealers can get information about ordering a minimum lot of six from Preston Brown of the Telefreeze Company at 516-288-4451.

Two guidebooks on specialized topics: cooking schools and South America's national parks.

"The Guide to Cooking Schools" by Dorlene V. Kaplan, in paperback and in its third edition, for 1991, has proved to be a solid value; letters to this department show how many people dream of attending classes in a foreign cuisine. The book lists 307 schools and 144 vocational-technical and junior college programs. The book is available at bookstores and elsewhere for $16.95, and from the publisher for the same price, plus a $2 shipping charge.

Shaw Associates, 625 Biltmore Way, Suite 1406, Coral Gables, Fla. 33134; 305-446-8888.

"South America's National Parks" by William C. Leitch covers 34 parks in Argentina, Brazil, Chile, Colombia, Peru, Suriname and Venezuela. Mr. Leitch has left out parks that require "a long expedition or great expense for aircraft or river transport," but his appreciation for wild things and fragile surroundings is intense. The author's black-and-white photographs are full of interesting detail: for example, bring-your-own hammocks swung on the deck of an Amazon River boat. There are plenty of maps as well. The paperback costs $15.95.

At bookstores or South American Explorers Club, Post Office Box 18327, Denver, Colo. 80218; 800-274-0568; postage and handling, $3.50. Ask for item 293.

The following three automobile gadgets may prove useful for drivers taking long - or short - trips.

To ease the use of seat belts, eight-inch-long sheepskin pads wrap around the belts and attach with Velcro, although you can slide them to the right spot. These keep the belts from chafing the neck or chest. But you should know that if you install these, the seat belt is no longer able to retract fully when you leave the car, so push the drooping belt back inside to avoid shutting it in the door and dirtying it. One pad is $7.95, two are $14.50, plus shipping by zone.

The Vermont Country Store, Post Office Box 3000, Manchester Center, Vt., 05255-3000; 802-362-2400.

To keep the countryside clean, there is a trash hamper of an adequate size - three-gallon capacity - that attaches to the back of a front seat with a belt that fits around the headrest. The outside is black nylon, the lining waterproof plastic. The stainless-steel frame snaps shut at the top. It could also hold baby toys. It costs $14.95.

Hammacher Schlemmer, 9180 Le Saint Drive, Fairfield, Ohio 45014; 800-543-3366; shipping, $3.50; also available from the MOMA Design Store (44 West 53d Street) and from the Museum of Modern Art's catalogue (212-708-9888).

For some time I have been interested in the roll-down shades that are applied to the inside of a car's side windows with suction cups or hook-on devices. My cousin in Fresno, Calif., who has been warned to avoid bright sun, has affixed one to the passenger-door window and says it has been effective. I thought that such a screen might be worthwhile to protect children riding in the back seat.

Dr. Leonard C. Harber, professor of dermatology at the Columbia-Presbyterian Medical Center and a leading expert on diseases caused by the sun, says it is unlikely that modern automobile glass, even if tinted darkly, screens out any of the damaging ultraviolet B rays.

For this reason he cautions people to wear sunscreen, even in an automobile, between 11 a.m. and 4 p.m. He points out that for the sun-sensitive, there are special Mylar screens, but that any sort of protection, particularly for children, will help. So the final automobile item on this list is the perforated roll-down screen for your car's side windows in the back seat. These screens come in many brands, with prices starting at $7.

Available at auto supply stores.

On the slightly larger scale is a redesigned version of a folding portable backrest that was popular in the 1930s. It is created out of two sets of 15-inch light wooden slats hinged on canvas to open like a clam, with a diagonal webbing strap on each side to hold the seat in a V for sitting.

This legless device rests on another seat or the ground, and thus makes it easier for those fragile of back to sit by the fire, in bleachers or in a canoe. The maker, Leslie Novak of Newburyport, Mass., who has named the item the Howdaseat, says she likes to use it on the train because she is able to swivel to face the window and still have her back supported. The seat costs about $40.

From the J. Peterman Co., it is $41.95, postage included: 2444 Palumbo Drive, Lexington, Ky. 40509; 800-231-7341. From the Solutions Catalogue, it is $39, plus $4.95 postage: Post Office Box 6878, Portland, Ore. 97228-6878; 800-342-9988.