Around the world, naked, on a bike - the first leg

The riders were campaigning against cars and their damage to the environment, many using their bodies a display for slogans.

Some just painted their bodies in colour while others featured wigs and hats.

Others stuck to underwear and many just kept to the theme as they cycled the streets, catching the attention of peasants.

Hundreds of naked cyclists rode through the streets of Mexico's capital on Saturday to demand respect from drivers in a city choked with some 4 million vehicles.

More than 500 men and women, half of them nude, pedaled along Mexico City's historic Reforma Avenue to the vast Zocalo Square, chanting, "Save your planet, use a bicycle!"

About 75 cyclists gathered in an Ottawa park Saturday to protest what they call their "indecent exposure" to pollution - and many were wearing nothing but sunglasses and sunscreen to drive home the point.

The gathering was part of the fourth annual World Naked Bike Ride.

The nude cyclists were outnumbered two to one by tourists and passersby.

A flier promoting the Tucson World Naked Bike Ride suggests you go "as bare as you dare," but lawyers warn that if you dare to bare it all, you may end up in jail. City Attorney Mike Rankin said Thursday that totally naked riders would be subject to Arizona's public-indecency statute, though he knew of no city plans to crack down. It was the first he'd heard of it.