Decades of statistics point to a societal retreat from the church wedding. Catholic marriage ceremonies have been in decline for 35 years -- from 426,000 marriages nationwide in 1970 to 212,456 in 2005, according to church data -- even as the number of Catholics continues to grow.

In response, some clergy in mainline denominations are trying to accommodate a more expansive view of the marriage ritual: conducting weddings outside of church, catering to interfaith couples, even permitting subtle changes in centuries-old vows.

The Rev. Frank Trotter of Metropolitan Memorial United Methodist Church, a Gothic cathedral on Nebraska Avenue in the District, has presided over weddings on Sugarloaf Mountain and at Rehoboth Beach, and he has crafted a variety of interfaith ceremonies that "show the diversity of God's love."

Another force competing with traditional denominations is the trend toward do-it-yourself ordination. The Universal Life Church of Modesto, Calif., has ordained from 18 million to 20 million people since 1962, chiefly for the purpose of officiating at weddings, said Andre Hensley, a director of the church. The Church of Spiritual Humanism, outside Philadelphia, has ordained more than 100,000 ministers since 2002.

"These are people who don't really fit into a regular traditional church, but they still have a sense of spirituality," said Richard Zorger, founder of the Church of Spiritual Humanism.

Zorger's church offers a Deluxe Clergy Pack for $89.95. Hensley's offers a Ministry-in-a-Box for $139. His church's Web site also offers, for $4.95, a Jedi Knight certificate.