By now you've filed with the IRS, or pleaded for more time. Some of you braved the gloom of night to meet the deadline. So maybe, with the pain still fresh, you're wondering what's in it for you.

Look on the bright side. "I don't know," mused the IRS press officer when asked to produce Commissioner Roscoe Egger. "Whatever he says to cheer up taxpayers might be misconstrued. But if you wanted to talk to him about our audit program or wraparound annuities. . ." At least try to look on the bright side.

Uncle Sam, it turns out, does want you to have some fun; he's spending your money to prove it, so why not reap the rewards?

From now till Sunday, for instance, you can climb into the cockpit of a North American Super Sabre or an A-5 Vigilante, both "hot" in the lingo of fighter pilots, don a helmet and get your picture snapped. Or stand beside a 1930s-vintage RT-14 Meteor, the plane in which aerobat Roscoe Turner did loop-the-loops with his pet lion Gilmore, both of them in aviator's scarf and goggles. It's all part of the National Air and Space Museum's BIRTHDAY BASH for the Paul E. Garber Preservation, Restoration and Storage Facility in Suitland.

The facility, which runs on half a million of a your tax dollars a year, also will let you watch craftsmen restore historic aircraft, tour two hangars housing 65 priceless planes, and -- while the supply lasts -- take away autographed photos of such as Chuck Yeager, he of the The Right Stuff, space shuttlers Joe Engle and Richard Truly, and World War II ace Francis Gabreski.

Hours are noon to 3, with free shuttle buses leaving from the National Air and Space Museum between 11:30 and 1:30. To get there by car, take Pennsylvania Avenue to Branch Avenue, turn right on Branch, follow it to Iverson Mall, make a left at the stoplight, and turn left again after one block. The facility will loom on your right.

This weekend, meanwhile, offers you plenty of other ways to get yours -- besides garden tours at the White House Saturday and Sunday and "panda information day" Saturday at the National Zoo (see Weekend's Best for details on both free events), here are some of the tax-paid treats in store for you:

CLASSICAL ARABIC MUSIC -- Saturday at 2 at the National Museum of American Art, corner of Eighth & G Streets NW, to go with a watercolor show called "Egypt: Day and Night." Egyptian musicians will play a qanun, a/k/a trapezoidal zither; a req, or tambourine; a nay, that is, a flute, and other traditional instruments.

BUYIN' FREEDOM -- a short play by William Hathaway, performed Saturday at the Museum of American History at half-hour intervals from 11 to 2. The story concerns a slave trying to buy his freedom from a plantation owner. Look for it in the Virginia Parlor of the Hall of Everyday Life on the museum's second floor.

A MODEL ROCKET LAUNCH -- Sunday at 1 at the Goddard Space Flight Center in Greenbelt. Ed Pearson, manager of the visitors center, said the Trailside Rocketry Club of New Jersey plans some 50 blastoffs and parachute recoveries, a spectacular show. To get there, take Beltway Exit 22-A and follow signs to the visitors center.

But maybe your tastes run to different delights. So you might try the Fairfax County Park Authority's GOBBLERS PROGRAM, Saturday morning at 8, wherein amorous wild turkeys are coaxed into public view. It's at Ellanor C. Lawrence Park in Centreville. Park naturalist Olin Allen explains:

"We'd like a small group of people, to keep it fairly quiet and well-contained, and we'll remain partially hidden in some bushes. We'll use mechanical turkey calls -- a diaphgram call and a box call--and tape recordings, and perhaps a decoy, and try to get some tom turkeys out of the woods. They're very secretive birds, but the mating season's here, so if we make the apropriate noises, they might be interested, depending on how amorous they are and which way the wind is blowing." The result: probably some posturing and strutting and, as a ragm ca remote possibility, actual mating. The latter lasts, he says, "a few seconds at most." Call 631-9566 for reservations.

Of course, there are tax-supported jollies beyond the weekend, too. When Her Majesty Queen Beatrix and His Royal Highness Prince Claus of the Netherlands come to town this Monday -- marking two centuries of friendship between the Netherlands and the United States -- a host of DUTCH TREATS will follow in their wake. There's a concert at the Netherlands Carillon in Arlington, Monday at 3:30; a celebration of Amity Day at Georgetown Park Mall, starting Wednesday morning at 10:30 -- "free music, free cheese and free Mayor Barry," says the National Park Service's Steve Siegel to describe the program -- and, starting Wednesday evening at 7:30, a band concert and fireworks on the Washington Monument grounds. Through it all, 900 tulip pots, installed by Park Service folk, will grace Memorial Bridge.

Any day of the week, meanwhile, your county extension agent probably is handing out loads of FREE ADVICE on ways to better your lot. Next Thursday night, for instance, the Prince William County Cooperative Extension Service presents "Color in Your Wardrobe," a workshop for putting life into your clothes.

"It's really my interpretation of the book 'Color Me Beautiful,' " says the volunteer instructor, home economist Sara Thomas. "Everybody's basically divided into four seasons, depending on the tones of their skin. For example, I've got ash tones to my hair, kind of blue skin with a lot of red in it -- which is typical for summer people -- and greenish eyes with a gray rim around them. So I look better in most shades of blue, from navy to pastel." Call 369-9262.

State-supported schools might also be good for amusement. Next Tuesday at seven, for instance, the University of Maryland's Parapsychology Club presents a PUBLIC LECTURE on the "Out of Body Experience, Soul Travel, Astral Projection" and related concerns. Says James Doyle, a self-described psychoanalyst who's giving the lecture, "I have students who have done so well in going out of their bodies, they've been able to check out the final exams the day before, and get straight As." The meeting's in Room 0220 of the Foreign Languages Building on the College Park campus.

Or shake hands with Roland Flint, who'll be taking part next Friday morning, April 22, in a reading of SHAKESPEARE'S SONNETS at the Folger Theater at 11. Flint, a poet and professor of literature at Georgetown University, just received a $12,500 grant from the National Endowment for the Arts. "It'll enable me to take off all of next year and work on my poems," says the Silver Spring resident. "I think I'll be going to New Zealand at the end of August."

Bargain-hunters, meanwhile, might check out the D.C. Police Department's monthly AUCTION OF IMPOUNDED CARS. "We have all kinds of things, from pure junk to good cars," said Lt. Clifton Porter. "I've seen some people drive away in Mercedes- Benzes. The only problem is that we never have the keys." Auctions are generally held the first Tuesday of the month -- the next one's May 4 -- at the Blue Plains Impoundment Lot. Watch the classified ads the weekend before.

Then you can always TOUR THE FBI, weekdays from 9 to 4 at the J. Edgar Hoover Building (use the E Street entrance between Ninth and Tenth Streets NW). You'll see technicians at work in crime labs, hear about famous ne'er-do-wells -- like the fellow who blew up his mother, plus the plane she was riding in -- and watch an agent shoot a .38 special and a Thompson submachine gun on the FBI's indoor firing range Don't mis a stop at the Crime Clock. "Folks," tour guide Tammie Kaufman said rightly the other day, "there's a murder committed every 23 minutes. So you before you leave the building, two people will have been murdered somewhere in the United States."

Or, for an experience in surrealism, look in at the BUREAU OF ENGRAVING AND PRINTING, corner of 14th & C Streets SW, weekdays from 8 to 2. You can see $1 to $100 bills being printed, examined by Treasury inspectors, cut from sheets and packaged for distribution. You can also buy whole sheets of dollar bills at the gift shop: $20.25 for a sheet of 16, $38 for a sheet of 32. "Most people keep the money in sheets," says Treasury's Allan Wibbenmeyer. "But if they got themselves into bad straits, I suppose they cold decide to cut them up, and the money would be as good for circulation as any regular bill."