If everything you see looks Mexican this weekend, you're getting a feeling soon to be shared by people in New York, Atlanta, San Antonio, Detroit, San Francisco, Oakland, Los Angeles and San Diego.

It's "Mexico Today," billed as the largest and most comprehensive presentation of contemporary Mexico ever to be organized in the United States. The symposium itself, in the OAS Hall of the Americas, will include a series of evening panel discussions of arts, politics and other aspects of Mexican life. Tied in with that, no fewer than 10 area museums and galleries will have special exhibits, and there'll be a film festival, performing arts, crafts demonstrations, classes, lectures and workshops - most open free.

The Corcoran will present a retrospective of the works of Mexico's premier photographer, Manuel Alvarez Bravo, who was profoundly affected by the cubistic, abstract works of Picasso and the Japanese printmaker Hokusai. Bravo strove to incorporate the techniques of these seemingly contrasting masters in his pictures. His photography not only expresses a personal point of view, but explores new ways of seeing and discovering his surroundings, and his technical prowess does not get in the way of his pictures' essential message an emotions.

His influence on subsequent generations of Mexican photographers is the subject of one of two smaller shows at the Corcoran: "Four Young Mexican Photographers." The other show is period photos by Tina Modotti, Paul Strand and Edward Weston, all friends and contemporaries of Bravo. These shows run through Thanksgiving weekend.

Mexican masks and clay figures from Guerrero are featured at the Renwick Gallery. A major form of folk art, masks are still an intimate part of Mexican religious life and festivals as well as a link with a country's ancient heritage. For generations, artisans in San Agustin have made animal and human figures in clay, and bowls and pitchers depicting human faces, reflecting a sense of fantasy and humor and striking in the range of their expressiveness.

Contemporary crafts are on exhibit through November in the windows of the Inter-American Development Bank. An outstanding piece is the orange wood chest, covered with coats of black and white lacquer in oriental fashion, and intricately carved with delicate images of birds, rabbits, foxes and foliage. Also on display are the woolen rugs, woven Persian-style, with traditional Mexican motifs and colors.