The 2004 Smithsonian Folklife Festival runs June 23-27 and June 30-July 4. The three subjects this year are: Haiti, Nuestra Musica (Music in Latino Culture), and Water Ways (Mid-Atlantic Maritime Communities). I'm especially interested in this last one, since that's my old stomping grounds (raised in Virginia by the coast).
Also, Screen on the Green: Outdoor Movies on the National Mall. UMD has a schedule listed. Films this year are:
July 19: All the President's Men (1976)
July 26: Dr. Jekyll and Mr. Hyde (1941)
August 2: Whatever Happened to Baby Jane? (1962)
August 9: The Thin Man (1934)
August 16: Mr. Smith Goes to Washington (1939)