LEGGIN' IT, DAY OR NIGHT

Lace up and grab a partner for the Foot Locker's 8K Partners Road Race, a 4.97-miler at 9 Saturday that's open to almost any two-person team. Between 7 and 7:45 male/female, professional, parent/child, sibling and other duos can register ($12 per couple; $8 single); if you don't have a partner, the sponsor will find you one. After the race, hosted by former Redskins coach George Allen, there'll be free pizza for everybody. It all starts at the Lincoln Memorial. 223-5403.

If you're not a morning person, the Potomac Appalachian Club's second annual 10-mile Moon Walk begins at midnight Saturday at Union Station and finishes, at 8 a.m. Sunday, in Georgetown. En route are stops at the Botanic Gardens, Jefferson Memorial, Vietnam Memorial, Lincoln Memorial and Arlington Cemetery, where there'll be a folk concert by the Dawson Singers. It's free; bring snacks, water and a flashlight. It'll be cancelled if the chance of rain is more than 35 percent. Call 224-0543 during the day or 296-6550 after 5.

FESTIVALS GALORE

Rock Creek Park Day and the Art Barn's 10th International Festival coicide noon to 6 Saturday at the Carter Barron Amphitheater with arts and crafts sales, magic and puppet shows and traditional song and dance from Argentina, Barbados, Indonesia, Finland and many other nations. Come hungry; there'll be lots of ethnic foods. 426-6719.

Put on your dancing shoes and get set for Glen Echo's Bluegrass & Old Time Music Festival noon to 6 Sunday. More than 30 bands, including old time and bluegrass groups will jam; if you're a musician, bring your instrument and join in. Both the calliope and merry-go-round will be open for children's rides and the Spanish ballroom will be full of Appalachian clogging, swing and square dancing. Free. 492-6282.

More international doings are at the Festival of Nations at the Tucker Road Sports Complex, 1772 Tucker Rd. in Fort Washington. There'll be something for everyone: Entertainment and activities between noon and 6 Sunday include the Trinidad and Tobago Head Wrapping Dancers, Foggy Bottom Cloggers, Ukrainian Easter egg painting, pasta making and a pinåata party for kids. Sporting events include 2K and 10K races at 9 (register at 7; $3 and $8). Free. 292-9006.

CIRCUS CIRCUIT

Run away to watch Circus Vargas Friday through Sunday at the Patriot Center (and Wednesday to October 5 at the Capital Centre). Among the 300 performers and 200 animals of the circus are the 20 lions and tigers of trainer Alan Gold, Soviet tightwire acrobats Bertalina Kazakova and Nikolai Nikolski and a clowning cast of dogs, llamas, ponies and camels. Tickets are $5 to $20. For a schedule: 432-0200.

LONG & WININ' ROAD

Your cup overfloweth at the 1987 Maryland Wine Festival, 10 to 6 Saturday and noon to 6 Sunday at the Carroll County Farm Museum in Westminster. For the $8 admission fee, you can taste 10 wines and listen to the music of a dozen bands, including the Monumental Brass Quintet, the Imagimime duo and the Peabody Ragtime Ensemble. Take I-270 to Rte. 32 west to Westminster; the museum's at 500 South Center St. 301/848-7775 or 301/876-2667.

ETHNI-CITY

Hardly procastinators, the Washington Saengerbund's Oktoberfest is 1 to dusk Sunday with oom-pah bands, children's games and Bavarian dancers. The menu boasts homemade potato salad, wurst and ku chen. It's at the German Orphan Home in Upper Marlboro, off Rte. 4 at Woodyard Road. It's $2, free for kids under 16. 585-7383 or 258-9355.

It's all Greek to the folks over at St. George's Church; at their 18th annual Greek Festival they'll be serving stuffed grape leaves, moussaka, shish kebab and roast lamb, among many other specialties. Some of the proceeds benefit the National Institutes of Health. It's at 7701 Bradley Boulevard. Call 469-7990.

Beginning at 7:30 Saturday, Centro de Arte's "Artistic Tribute to the Chilean People" features New Song music by vocalist Makeka, Andean group Hinantillan and a posthumous photography exhibit by Rodrigo Rojas. It's $6 at Casa del Pueblo, 1459 Columbia Rd. NW. 466-5419.

Eastern Europe is closer this weekend with an evening of Ukrainian Music and Dance at 8 Saturday at the Thomas Jefferson Community Theater, 3501 South Second St. in Arlington. Besides the high-speed leaps, twirls and acrobatics of the Lyman Ukrainian Dance Ensemble, there'll be bandura music and and a folk art exhibit. It's $5. For reservations, call 558-2165.

St. George Antiochian Church presents its 15th annual Middle Eastern Festival 10 to 8 Saturday and 1 to 5 Sunday with the live Arabic entertainment of vocalist Hassan and the Al-Mouna Ensemble. Plenty of food, including gyros, kibbeh and baklava will be for sale. It's free at 4335 16th St. NW. 723-5335.

OPEN CATHEDRAL

The Washington Cathedral welcomes visitors 10 to 5 Saturday for its annual Open House Festival. Beside tours of the 80-year-old but still-abuilding structure (pick up free tickets at 8:30 and 11:30), there'll be music by the All Seasons Band, Music Antiqua, Ironweed, Bethesda Chamber Singers and American Jubilee. It's at Wisconsin and Massachusetts NW. 537-6200.

REST OF THE BEST

Ocean City's 13th annual Sunfest is 10 to 10 Friday and Saturday and 10 to 6 Sunday at the inlet parking lot with music, arts, crafts and food. Free. 301/289-2800 . . . Burke Center Conservancy's 11th annual Fall Festival is 10 to 5 Saturday and Sunday with craft sales, rock bands and children's games. It's at 6060 Burke Center Pkwy. 978-2928 . . . It's a free Reggae Festival with six local and New York-based bands noon to 9 Sunday at Banneker Recreation Center, 100 Euclid St. NW. 232-8226.