Baltimore gets a jump on the Preakness Friday with such offbeat events as the finals of the World's Fastest Typist Contest (11 a.m. at the Omni International Hotel) and a crab race and pistachio shucking contest beginning at 1 (at the Harborplace Amphitheater). Then at 7:30, the WBAL Preakness Parade marches down Charles and Pratt streets to Pier 5 in the Inner Harbor. Saturday is race day at Pimlico. Gates open at 9 a.m. for a day-long infield party featuring 11 local bands and a lacrosse game (you're welcome to bring barbecues, coolers and tents). The actual running of the Preakness Stakes is at 5:30. Tickets, $7 (grandstand and infield) and $10 (standing room only in clubhouse), are available at the gate. For details, call 301/837-4636. All on the Mall
There's free fun around the Air and Space Museum all weekend long.
*The Commodores, the Navy's 18-member jazz band, kick off their Friday concert series at noon on the museum's west terrace. The free concerts continue through May. 433-2525.
*Providence Hospital celebrates its 125th birthday Saturday from 3 to 7:30 on the field just east of Air and Space. Washingtonians born in Providence will be treated to birthday cake, and the general public is invited to share in the other festivities. Entertainment is courtesy of the 100-member Paul Hill Chorale, the brass band Heritage Americana, the Old Dominion dancers with 19th-century country dancing, and a fife and drum band. A living-history Civil War encampment and exhibit will be set up. And Abe Lincoln (Alex Townsend of the National Park Service) makes a special appearance. 269-7350.
*The night crews working at Washington restaurants get their day in the sun at the Finlandia Vodka Waiters Race Sunday. About 170 waiters and waitresses from 70 restaurants will be running a 1/4-mile course carrying trays with full glasses of water. Redskin Joe Jacoby officially starts the 12 heats beginning at 1. The winners in the men's and women's divisions each receive $250. The Capital Jazz Ensemble provides the entertainment. Openings are limited, but latecomers may be able to register on race day between noon and 1 on the Mall between the Air and Space Museum and the National Gallery. Proceeds benefit the Multiple Sclerosis Society. 526-8000. Two in One
There are craft fairs and there are concerts. You get both at the 12th Annual Frederick Craft Fair. Providing the music are songwriter John Sebastian, formerly of the Lovin' Spoonful, and singer David Bromberg. They perform together at noon and 3 on Saturday and Sunday. More than 300 craftsmen demonstrate such skills as glassblowing, stone carving and sheep shearing. You can even see blacksmith Danny Hurwitz forge iron using the same technique he's employing for the bronze gates of the soon-to-be restored Statue of Liberty. Bring your appetite too -- booths will be selling such treats as Maryland crab cakes, fried oyster sandwiches, grilled Mongolian beef and Pennsylvania Dutch funnel cake. Admission is $4; children under 12 are free. The fair runs Friday through Sunday from 10 to 6 at the Frederick Fairgrounds, at the junction of I-70 and I-270. 301/662-1966. Blowin' His Horn
Tenor saxophonist Billy Harper brings his quintet to D.C. Space for three shows on Saturday. Harper has performed with Max Roach, Gil Evans and Art Blakey and the Jazz Messengers. Showtimes are 8, 10 and midnight. Tickets are $10 at the door, Seventh and E streets NW. 347-4960 or 347-1445. Shell Shots
Camera and history buffs can get a telling account of war in Behind the Lines and Beyond the Call: The Photographer's Role in War, a free panel discussion held in conjunction with the exhibit "The Indelible Image: Photographs of War." Saturday from 1:30 to 5 at the Corcoran, five photojournalists -- including Constance Larrabee, Time magazine's Dirck Halstead and Gilles Peress of the international photo agency Magnum -- will discuss their experiences covering wars and then field questions from the audience. Four of the five have their work in the show. Seating for 200 is on a first-come basis in the Frances and Armand Hammer Auditorium, 17th Street and New York Avenue NW. 638-3211. Rest of the Best IN TOWN
Sts. Constantine and Helen Greek Orthodox Church celebrates its annual Greek Festival with traditional food, dance, music and crafts. Hours are noon to 9 Friday through Sunday. The church is at 4115 16th Street NW. Free. 829-2910 . . . More than 1,000 Washington public school kids perform at the City-Wide Music Festival Friday at 8 in DAR Constitution Hall, 18th and C streets NW. Tickets, $3 and $5, are available at the door or by calling 393-3600 . . . The 7th Annual National Capital Cactus and Succulent Society Plant Show is from 9 to 5 Friday through Sunday at the U.S. Botanic Garden, Independence Avenue and First Street SW. Free. 225-7099 . . . Eight local designers are represented at Catholic University's Hartke Theater in Help Is in Fashion, a fashion show benefiting the American Red Cross Disaster Relief Fund this Saturday at 8. Tickets, $15, include the show and a buffet and are available at the door. 424-2309 . . . There'll be rap and reggae bands, African drummers and dancers among the entertainment at the 15th Annual Malcolm X Day Sunday from noon to 7 at the north end of Anacostia Park off the 11th Street Bridge SE. Free. 544-0880 or 684-6104 . . . The works of Chopin, Beethoven, Ravel and Debussy are featured in the final Bethune Museum concert of the season this Sunday at 3. Tickets, $1, are available at the door, 1318 Vermont Avenue NW. 332-1233. IN MARYLAND The Masterworks Chorus performs Haydn's "The Seasons" (in English) Saturday at 8 in St. Bernadette's Church, 70 East University Boulevard, Silver Spring. $10 at the door. 593-5919. IN VIRGINIA
McLean Day Sommeranfang celebrates German culture Saturday from 11 to 4 with traditional German food and beer, crafts, music, carnival games and storytelling. It's free and at the McLean Center, 1236 Ingleside Avenue. 790-9248 . . . The Barns of Wolf Trap, 1635 Trap Road in Vienna, hosts a performance by jazz artist Kenny Rankin Saturday at 8. Tickets, $12, are available at the door or by calling 938-2404.