Sometimes you can't make it up any weirder than it actually is. That definitely was the case on June 14, when a pair of environmental pranksters managed to promote themselves as keynote speakers at the Gas and Oil Exposition - aka GO-EXPO 2007 - in Calgary.

Masquerading as officials from ExxonMobil and the U.S. National Petroleum Council, the two appeared before an oil industry audience and the buzz was that they would deliver long-awaited conclusions of a study commissioned by U.S. Energy Secretary Samuel Bodman.

They actually offered something a bit more revolutionary: a new fuel called Vivoleum, to be used in the event of a global climate calamity and made "by transforming the billions of people who die into oil."

"We need something like whales, but infinitely more abundant," said the faux NPC rep "Shepard Wolff" - in reality, Andy Bichlbaum of the satirical duo the Yes Men. He then described the technology that would render human flesh into Vivoleum, a new Exxon product, with 3-D animations and a PowerPoint presentation.

"Vivoleum works in perfect synergy with the continued expansion of fossil fuel production," noted the ersatz Exxon rep "Florian Osenberg" (Yes Man Mike Bonanno). "With more fossil fuels comes a greater chance of disaster, but that means more feedstock for Vivoleum. Fuel will continue to flow for those of us left."

The oil industry crowd listened attentively through the presentation and only started looking quizzical after the speakers began distributing memorial Vivoleum candles, putatively made from the remains of an Exxon janitor who perished after cleaning up a toxic spill. The candles were really made of paraffin, beeswax and bits of human hair, "so they actually stank, as you might expect if you were burning a human being," Bichlbaum said. The candles were mounted in boboches - little circles of printed paper to keep the melting wax off people's hands - printed with the message: "80 percent Vivoleum" and commemorating an actor named Reggie Watts, who played the janitor in a tribute video shown at the event.

"At this point, people have gone through disgust to realizing that they've probably been had, which is just fine," Bichlbaum said later by telephone. After that, the conference organizer charged up to the stage, made them stop the show and hustled Bonanno off. Bichlbaum, still in character, told reporters who clustered around him, "Well, we've got to turn humanity into fuel or do something with them, it'd be cruel not to do something with all that resource going to waste."

Calgary police were summoned but no arrests were made, and the Yes Men left without further incident.

The two have been orchestrating these kinds of events since 1999, when a satirical Web site they made that was pegged to the Seattle meetings of the World Trade Organization was mistaken for an official WTO site and the Yes Men got "accidental invitations" to speak to various gatherings. Bichlbaum acknowledged that the GO-EXPO presentation was near the pinnacle of prankdom.

"I would say this is a really good one because it's the kind of industry that's most evidently destroying the planet and destroying our chances for survival," he said. "And these people that we were speaking to are the most directly involved in destruction of any audience we've spoken to."

The Yes Men see themselves as political activists, but Bichlbaum accepted the title of environmentalist. "I think you have to be ... We all depend on the environment so much right now. We're not talking about just destruction of nature, we're talking about destruction of humanity with climate change and the way these things are going. It's not a matter of environmentalism, it's a matter of wanting to survive."

Neither ExxonMobil nor the National Petroleum Council would comment. The conference organizers issued a statement saying they had verified that their keynote speakers were not who they pretended to be.