By Allen Nevins and Nancy Borgenicht WORLD PREMIERE PREVIEWS: June 18 - June 20 OPENING: Friday, June 21, 2002 RUNS: June 18 - August 25 So whats there to sing, dance and laugh about this year How about drought, water and oil. Elvis, aliens and Republican redistricting. Public land and private property. Trephination, Vagina Monologues and the Constitution. Black helicopters and herds of gaseous ...