A decade ago, I became ordained in the Church of Latter-Day Dudes so I could officiate a wedding in Texas; it is, apparently, legal for the Dude to abide over the institution of marriage in that state.
But that was a different time, before an apathetic cosmic horror who craves nothing but worshipful death from his followers became an appealing alternative to the current leadership of several powerful nations. Which is why I've renounced by Dudeist vows, and am now ordained in the First United Church of Cthulhu.
In order to perform weddings, some states do require a letter of good standing from the local governing authority of your church; I learned this the hard way when I officiated a wedding in Massachusetts, and the governing authority for the Church of Latter-Day Dudes was characteristically lazy and unresponsive. Luckily, the website for the First United Church of Cthulhu offers clear instructions for this:
You are the gibbering voice, the insanity-inducing dreaming mind blast, the writhing real world living tentacle of Cthulhu! As the head priest and exalted avatar of Cthulhu I ordain thee as a priest of Cthulhu. As such, you are granted by the power of Cthulhu to physically sign your own Letter of Good Standing. Or ordain a friend and have them sign it.
If you really need my signature as the Head Priest it's gonna run you $20. But that includes shipping and the cost of having it notarized. And I'm sorry your state sucks. You should really summon a few star-spawn and take care of that problem.
The church also offers several sample marriage vows to aid in your ceremonial
Yog-Sothoth knows the gate. Yog-Sothoth is the gate. Yog-Sothoth is the key and guardian of the gate. Past, present, future, all are one in Yog-Sothoth. And so it is that today we are gathered here to unite [Being #1] and [Being #2] as one. These rings are a symbol of Yog-Sothoth's congeries of iridescent globes, his malign suggestiveness is now also their malign suggestiveness. These rings are the key and guardian; the gate is their future together. Let all behold them as they enter into a world of new tomorrows, knowing that no Old Ones may break them apart nor tread them asunder.
Life is a hideous thing, and from the background behind what we know of it peer daemoniacal hints of truth which makes it sometimes a thousandfold more hideous. Yet [Being #1] and [Being #2] have defied such astronomical odds and found that truth in one another. And together, each makes the other's life about 999 times less hideous.
Anyway, if you want to join the church, you can. Or I can legally officiate your wedding, if you ask me nicely.
Image: Robert Couse-Baker / Flickr (CC 2.0)