On the March Hit your stride Sunday in the March of Dimes WalkAmerica, the nation's largest walk-a-thon. With three different 30K courses in the area, there's bound to be one near you. In the District, the start is on the Washington Monument grounds near the Sylvan Theater. In Maryland, it's at White Plains Park in Waldorf, Charles County, and in Virginia, it's at Lake Fairfax Park in Reston (Routes 7 and 606). The walk begins at 8 (and remember it's Daylight Saving). If you poop out along the route, a van will be making the rounds to pick you up. Registration, from 7 to 8 a.m., costs $10 and benefits the March of Dimes Birth Defects Foundation. 370-0444. Dandy Deco

Art deco buffs can have a field day at the Third Annual Exposition of the Decorative Arts hosted by the Art Deco Society of Washington. Sunday from 10 to 6 at the Shoreham Hotel, exhibitors from eight states show off furniture, clothing and interior design that was popular from 1920 through the 1940s. You may find just the lamp you've been waiting for on sale in the Ambassador Ballroom. There'll also be films, slides and lectures, including one on American diners, from noon to 5 in the Congressional Room. Admission is $4 at the door, 2500 Calvert Street NW. By Metrorail, exit from the Woodley Park Metro station on the Red line. 231-3793. Latin Legends

Spanish-speaking culture is in the spotlight this weekend at the Latin American Book Fair, a festival celebrating Latin arts. You don't need to speak Spanish to enjoy the fair. There'll be subtitled feature films from Argentina, Mexico, Colombia, Ecuador and Peru and videos about such well-known Latin authors as Gabriel Garcia Marquez and Manuel Puig. You can pore over thousands of books in Spanish, English and Portuguese and hear scholars of poetry, literature and translation in panel discussions (in both English and Spanish). There'll also be events for children, crafts, food and an Andean folk music concert Sunday beginning at 12:30. The free fair runs Saturday and Sunday from 10 to 10 in Building 41, University of the District of Columbia, 4200 Connecticut Avenue NW. By Metrorail, exit from the UDC/Van Ness Metro station on the Red Line. 282-7538. Homes Sweet Homes

Area house tours are in full swing, so if you need to get out of your house and into someone else's, then by all means . . .

*Take a peak at how Georgetowners live on the 59th Annual Georgetown House Tour from noon to 5 on Saturday and Sunday. Among the 14 featured homes are an Italian villa and a converted 1813 farmhouse. Seven homes will be open each day. Tickets, $10 per day, are available at the beginnning of the tour at St. John's Church, 3240 O Street NW. 338-1796.

*Or check out Maryland's largest house tour, the 49th Annual Maryland House and Garden Pilgrimage, which kicks off a week-long exploration of seven counties this Saturday. On that day Charles County highlights 14 homes, gardens and farms. You can get your guide and tickets at the Econo Lodge at the junction of Routes 301 and 6 in La Plata.

On Sunday, you can visit 23 sites in Anne Arundel County. Information headquarters are at the Hammond-Harwood House at 19 Maryland Avenue in Annapolis. Hours are 10 to 5 each day; tickets are $10 per day. The tour continues through next Sunday. 762-1492 or 301/821-6933.

*And as long as we're on the subject, it's not too early to make plans for the 40th Annual Goodwill Embassy Tour slated for Saturday, May 10. In this event, which tends to sell out, shuttle buses take you to eight embassies. This year they include those of China, Colombia, Indonesia and Great Britain. Tickets are $15. 462-6587. Jazzmattazz

The Leaders, an ensemble of jazz lions now on international tour, play D.C. Space for three performances on Friday. The sextet includes Chico Freeman, Lester Bowie and Kirk Lightsey. Showtimes are 8, 10 and midnight. Tickets are $12. Then on Saturday, two top European jazzmen, Peter Bro tzman (tenor sax) and Han Bennick (drums) perform together at 8 and 9:30. Tickets for that show are $8. Tickets for both nights are available at D.C. Space, Seventh and E streets NW. 347-1445. Rest of the Best

IN TOWN Pete Seeger tops the bill in a concert of labor ballads Saturday at 8 in Lisner Auditorium, George Washington University, 730 21st Street NW. Tickets, $10 and $12.50, are available at Ticketron outlets (800/233-4050) and at the door. 965-3433 . . . Also at Lisner is an Irish Spring Benefit, a concert performance by six Irish and American artists Sunday at 3:15. Tickets, $10 and $25, are available at the door or in advance at Common Concerns Bookstore, 1347 Connecticut Avenue NW. The event is sponsored by Mt. Carmel House Women's Shelter. 289-6315 . . . Twenty-four men's and women's teams compete in the 20th Annual Cherry Blossom Festival Rugby Tournament on the Mall near the Lincoln Memorial. Games are continuous from 9 to 5 on Saturday; from 9:30 to 4 on Sunday. Free. 244-1478 . . . Woodward and Lothrop in Chevy Chase hosts its Third Annual Drive-In Movie Night Friday at 9 (gates open at 8) with a showing of "Off Beat," starring Meg Tilly and Judge Reinhold, in the store's upper level parking lot. Tickets, $10 per car (includes popcorn and pop), are available by calling 879-8753 or 654-7600, ext. 315. Proceeds benefit Hands Across America.


Twenty-three clans and societies celebrate the Eighth Annual Southern Maryland Celtic Festival and Highland Gathering Saturday from 10 to 6 in Kings Landing Park off Route 4, 20 miles south of Upper Marlboro. There'll be Celtic food and dance, as well as fiddling, piping and athletic competitions. Admission is $4 for adults; $2 for children and seniors. 301/535-3274 or 301/535-0292.