You realize, of course, that after this weekend, that's it. Poof.

Back to school. Back to work. Back-to-back two-day weekends 'til pumpkin harvest. The annual three-day change of life known as Labor Day Weekend is upon us -- heralding the official end, despite what Bob Ryan and your desk calendar say, of another Washington summer.

Sure, go on and panic. Cry if you want to; it might bring some color to your face. But do keep this in mind: Labor Day is the time to make up for lost opportunity. Even if you've already been to the beach (pool, park, Fiji Islands) this summer, or somehow managed to otherwise escape the mysterious will-sapping power of the Federal Triangle, it is time for one more lasting impression to keep you warm when the weather won't.

To put it another way: Such balmy pursuits as basking and body surfing just don't go after the Redskins start playing.

The Redskins start playing Monday night. This is your LAST CHANCE.

However. In the event that you plan to spend the next three days at home, say, stripping furniture, do yourself a favor:

1. Stop reading immediately and open this section to the centerfold.

2. Spread the opened section on the floor beneath the furniture, and put on some gloves.

The rest of you come with me. FINAL BEACH There are a number of methods of becoming the tannest person on your block to rake leaves, but one of the most sure-fire has got to be a trip to the beach this weekend. Say, REHOBOTH BEACH, Delaware. Unless you take the ferry from New Jersey (and Labor Day's the last chance for the ferry's hourly departure summer schedule), you almost have to cross the Bay Bridge to get to Rehoboth; this being Labor Day Weekend, good luck. Take somebody you haven't talked to in a while. (Also, hit the restroom before you hit U.S. 50.) Rehoboth, like most municipalities with access to the Atlantic, doesn't have to plan special events to drag people out on the last official summer weekend, nossir. But Rehoboth does have a Bandstand, there at the ocean end of Rehoboth Avenue, and Friday night there's an 8 o'clock show by Bobbe's School of Dance. Tomorrow, dance at 6 p.m. is followed by the Delaware Concert Band at 8 at the Bandstand. Sunday it's the U.S. Army Volunteers at the Bandstand, followed by Miss Delaware's official send-off to the Miss America Pageant. On Labor Day itself, after a show by the Banjo Dusters, some 25 Rehobothites (Rehobothians?) band together, loosely, for the traditional "Piping Out" ceremony. Yes. The traditional "Piping Out" ceremony. "We do it to say goodbye to the summer season," says Susan Stone, executive director of the town's Chamber of Commerce and a kazoo player of some note (though she's not always sure which one). "Everyone, led by Sammy Ferro and his trombone, rides the Jolly Trolley down Rehoboth Avenue, wearing funny hats and signs, to say goodbye to the summer season and visitors. Some of us don't play instruments too well." Well, okay. You'd act happy too, if you knew hundreds of thousands of out-of-towners were about to leave you and your beach relatively alone for a month or so of relatively beach-like weather. (That, of course, is another story.) This weekend's also your last chance to fight both the crimson-skinned and the tide for blanket space on the beach, a timeworn summer tradition for transplanted Washingtonians. As in OCEAN CITY, Maryland, for instance. "Be lucky if you find 10,000 people in 101/2 miles after Labor Day," says Robert Craig, captain of the Ocean City Beach Patrol. "But before that, on a weekend -- 250,000, maybe 275,000 people." That goes for this weekend, especially. But if you're looking to meet generally young, generally single, generally sun- bleached men -- yes, lifeguards -- your pickings are already slim, Craig says. "Regular season, we have about 130 guards," Craig says. "Right now, I'm already down to 62, 63. We get people from all over the country -- California, Florida, Colorado -- and a lot of them need a few days or a week to get to school, you know. We'll get some more in this weekend, kids going to Towson State, Catonsville Community College, University of Maryland. But we'll regroup after Labor Day, and we'll have maybe 40, 45 people through October 15 or so. Depends on the weather."

VIRGINIA BEACH is located on the far side of Richmond, which is located on the far side of a good deal of construction along I-95, but the trip's no worse than the Bay Bridge route, especially for a three-day stay. Bear in mind that U.S. 1, mainly four lanes but undivided, parallels I-95 closely; and consider U.S. 17, picked up at the bypass below Fredericksburg, as an alternate route to the Tidewater. It passes through some lovely Northern Neck countryside and Tappahannock, one of Virginia's friendliest towns. On the way into Virginia Beach on the Route 44 expressway (there's a modest toll), you'll pass the city's new Pavilion -- and beneath its striking concrete-and-glass arches you'll find Virginia Beach's annual Shakespeare by the Sea Festival. Friday night is "As You Like It," and Saturday night -- the last night of the festival -- is "Measure for Measure." Tickets at any Ticketron or call 804/428-8000. If nightlife -- or more specifically, dancing -- is an essential part of your final flingery, stop in at Pascal's (313 Laskin Road, 804/428-3831), whose self-wrought "King of the Clubs" image translates into a very crowded dance floor -- through this weekend, anyway. (Crowded dance floors are one of the best ways to acquaint oneself intimately with the latest fashions in stepping-outwear -- and with those who wear them, of course.) Hotcakes, one of the better top-40 bands around Tidewater, starts its sets at 9 p.m., Friday through Sunday. Cover is $3. LAST-CHANCE CITY Great idea. I understand everybody else will be out of town. The Frisbee, a disc-shaped hardy perennial, is nevertheless more active in the summer than the winter. As usual in Washington, it goes out with a bang (more of a whoosh, actually), in Washington's ultimate final fling: The 7TH ANNUAL SMITHSONIAN FRISBEE DISC FESTIVAL happens this Sunday on the Mall -- sponsored by the National Air and Space Museum, and featuring noncompetitive freestyle routines and demonstrations by experts, some of whom are dogs. Also, disc instructors from around the country will be about to help you perfect your pitch. Free. Call 357-2700. If you've been meaning to get to one of your LOCAL POOLS, you have till Monday. That's when virtually all the outdoor pools in the metropolitan area close -- including those in Alexandria, Montgomery County, Prince George's County and those run by the Northern Virginia Regional Park Authority. Too late in the District -- its outdoor pools closed last Sunday. Most of the SMITHSONIAN MUSEUMS return to normal hours (10 to 5) after Monday, and because relatively few people spend Labor Day hereabouts, this weekend is as good a time as any in the summer to visit -- especially between about 6 p.m. and closing time at 9. If you're into American history, head into American History for Hollywood's version thereof, namely its "M*A*S*H" exhibit. If you're looking for last chances in town but you're going away for the weekend, you can still catch the last big-band concert at the SYLVAN THEATER on the Ellipse, by the Charlie Cliff Orchestra, 8 p.m. Tuesday. Free. Finally, Alexandria's last summer TWILIGHT CONCERT at Fort Ward Park is next Thursday at 8 -- featuring, as is traditional in the Scottish-founded port, the Alexandria Pipes and Drums, and the Scottish Country Dance Society. This is also free. This is also it.

NEXT WEEK: Fun With Snow Shovels.