2006 San Francisco Gay Pride Parade

This weekend's pride celebration in San Francisco caps a monumental year in the history of the gay, lesbian, bisexual and transgender community, with unprecedented advances on same-sex marriage and a constant presence in popular culture, thanks largely to two gay cowboys on the big screen.

Those issues fueled the debate on gay rights in churches, schools, courtrooms, locker rooms, boardrooms and nearly every other segment of society, and leaders in the gay and lesbian community believe they are at the pivotal point in their movement.

San Francisco's transgender community commemorated a pivotal moment in its history Thursday -- a little-known riot that happened 40 years ago. But the community is also thanking an unlikely ally: A straight cop who in the 1960s befriended transgender people in the Tenderloin and advanced the gay, lesbian, bisexual and transgender movement in the city.

Elliot Blackstone, a retired police sergeant who is now 81, will be a grand marshal in Sunday's annual pride parade down Market Street.