Earlier this week, it was reported that some airlines were considering charging passengers based on their weight.

Then, an advertisement in Friday's Philadelphia Inquirer and Daily News suggested flying from Philadelphia to Denver for $1.90 per pound -- roundtrip fare based on total weight of passenger and passenger luggage.

Its Web site calls Derrie-Air the world's first carbon-neutral airline. The Web site claims the airline will plant trees to absorb the carbon released by its planes.

The site also gives price quotes based on weight from Philadelphia to a variety of destinations, including $1.40 for every pound to Chicago, and $2.25-a-pound to Los Angeles.

Could this be real? It was in the papers. In fact, there were a lot of ads in the papers.

But if you scroll all the way down, the site says, "Smile. We're pulling your leg."

The entire thing is a fictitious campaign by Philadelphia Media Holdings, the company that owns the Inquirer and Daily News.

The Web site says the campaign was designed to test the results of their advertising and to stimulate discussion on this environmental topic.