JUST because you are at home doesn't mean you have to be bored. There's a world of fun, food, fashion and fitness just outside the door, maybe even at the door.

In fact, wasn't that the doorbell?

DRESSING UP -- First, change out of your weekend rags and put on something new, something exciting enough to change your mood. What? You have nothing exciting or new? (Besides the autographed Barry Manilow T-shirts, of course.) Better call Your Personal Shopper (471-0598), where Lola Steinhoff will do your shopping for you -- even at the last minute. She'll pick out an evening dress, tuxedo, shoes, jewelry or almost any other item. The fee is based on time and mileage, but a two-hour shopping assignment in the area would run about $50 (not including the purchases, of course).

FOOD FOR THOUGHT -- Now that you're dressed, let's consider the evening. Forget the frozen turkey with stuffing, mashed spuds and green surprise. You can eat well at home without going out. If you live in the District (or in Rosslyn), you can call Order In (265-5665), which will bring you a full meal, delivered either within an hour or at a prearranged time, from a number of different restaurants. You can order Indian fare from Bombay Palace, American from Jo & Mo's, cajun from the New Orleans Emporium, Spanish and Mexican from La Plaza, Chinese from Szechuan and sandwiches from Le Sorbet. The cost is a 15 to 20 percent service charge, about what you would leave as a tip. For a similar tab, Takeout Taxi will bring you meals from four Herndon-area restaurants: Quicksilver's, Tortilla Factory, Hobo's Pizza Gourmet or Yenching's. If you live elsewhere, you might have to settle for pizza.

THE VCR IS YOUR FRIEND -- Renting tapes can be expensive, and taping those 3 a.m. classics can drive you batty, but listen: You can get them for free or for a small fee at some local libraries.

The D.C. Public Library charges $2 per title, with the tape due back the next day the library is open. The tapes can be taken out and returned only at the Martin Luther King Library (Room 226, 901 G St. NW, 727-0321). The library has about 1400 titles in stock, including such recent releases as "Raising Arizona" and "Platoon."

Prince George's public libraries charge $1 a day for VHS and Beta, and $1 to $4 for 16mm movies. (The library considers Friday through Monday as one "day.") Popular films should be reserved, but each branch has its own collection that can be checked out, just as you would a book. Recent releases include "An American Tail" and "The Lady and the Tramp" (699-3500).

Montgomery County libraries have 1500 tapes/800 titles in the browsing collections in Bethesda, Rockville, Gaithersburg and Wheaton. The Special Needs Library, 6400 Democracy Blvd., Bethesda, has tapes giving advice on how to cope with various handicaps. The tapes can be taken out for two days for free. Late fines are $1 a day. You cannot reserve them (279-1940).

Alexandria libraries have about 100 tapes you can take out free for two days; after that it's $1 a day (838-4555).

In Arlington, about 900 tapes are available only at the main library at 1015 N. Quincy St. The tapes can be checked out only by county residents; a separate collection is available to students of the Northern Virginia Community College. Checking out the tapes is free, but you must register at the audio/visual desk. You can keep the tapes one or two days, depending on whether it is part of the reserved or browsing collection (284-8181).

In Fairfax, about 13,057 tapes at the six regional libraries: Fairfax City, George Mason, Pohick Regional, Reston Regional, Sherwood Regional/Alexandria and Tysons/Pimmit. Tysons/Pimmit also has laser and video discs. All can be checked out free for three days; it's a $1-a-day fine thereafter (246-5858).

REACH OUT AND TOUCH SOMEONE -- The telephone is a wonderful device. It allows you to reach beyond those walls, to get in touch with someone. But sometimes they don't answer. Then what? Well, you could try Dial-a-Miracle (if you need one) at 620-5084; Dial-a-Phenomenon, the Smithsonian's Earth and Space Report (Jupiter is getting awfully close) at 357-2000; Dial-a-Prayer (don't lose hope) at 532-3033; for balance, consider Dial-an-Atheist (280-4321), for the dope on the "wonderful world of atheist sanity."

REACH OUT AND TOUCH EVEN MORE -- Take out your frustrations by calling WMAL's sports guru Ken (Yah Next!) Beatrice or psychiatrist Dr. Joe Novello at 432-9625. They'll commiserate with you. Novello is on weekday nights at 7; Beatrice follows at 9 for two hours. If Ken's stats don't lull you to sleep, give Larry King a ring. He hosts a national call-in radio show at WTOP-AM/1500 at 11 p.m. Monday through Friday. The number is 685-2177.

A DOCTOR IN THE HOUSE -- Don't waste your weekend. Have your annual physical, right in the privacy of your rec room. Call Geodan, which will send a doctor out, 24 hours a day, 365 days a year, to check you out and fix your ills. The cost is $100 (they take credit cards). Call 800/262-4362.

IF THE DOG GETS SICK -- Don't fret, call Petvacx , which offers mobile veterinary service in the Maryland suburbs. 762-3955. Dr. Flo Mitchell makes house calls mainly in the District and Northern Virginia. The vet fee is $27 to $33 for a house call plus medication and treatment. 620-3919.

GETTING FIT -- Pro to Home Fitness Specialists come to your home, evaluate your fitness and design a program to help you shape up. You get a personal instructor who will oversee your exercises and nutrition. The rates are about $50 per hour. 654-0821. Body Balance will teach you the Chinese martial art of Tai-Chi Chuan in your home. The fee: $65 an hour. 972-5644.