FOR A LABOR DAY WEEKEND LOADED with glam, gangsters and girth, New Orleans’ French Quarter is the place to be. The 34th annual Southern Decadence festival, which evolved over the years from a party for a few friends to a six-day street party attended by more than 100,000 people, runs this year from Aug. 31 to Sept. 5. Unofficially dubbed the “gay Mardi Gras,” Southern Decadence is filled with dozens of parties and thousands of uninhibited gay men frolicking in the street in search of beads and brethren. The event culminates with a Sept. 4 parade featuring elaborate and...