Rihanna in the April 2011 issue of Vogue. Photo by Annie Leibovitz

*Rihanna, who covers the new April 2011 issue of Vogue, is joining Taylor Swift and Selena Gomez in a campaign to force restaurant owners to charge for tap water to help fund clean drinking fluid around the world.

The singers have added their name to UNICEF’s Tap Project, which urges restaurants to ask diners to pay $1 for tap water they would usually receive for free.

Fans who donate money to the cause will then get the chance to win a special drink – a bottle of water filled from taps at the stars’ homes.

Rihanna's Tap Water

In one of the advertising posters highlighting the initiative, Rihanna poses next to a bottle of her personalized water with the words, “Rihanna Tap Water. Not your typical tap water, unless of course, you live next door to Rihanna.”

A message on the UNICEF Celebrity Tap website reads, “Celebrities have donated their own tap water to help raise awareness of the world water crisis. Donations enter individuals in our sweepstakes to win an esteemed collection of these famous tap waters.”

Meanwhile, Rihanna is the cover girl for the Vogue’s April 2011 issue. During the photo shoot seen in the video below, Vogue’s fashion editor Tonne Goodman has RiRi in Hérve Léger, Alexander Wang, Lanvin and Chloé.

Back in January, Rihanna tweeted: “Just wrapped my first American Vogue cover shoot with Annie Leibovitz…Rah! #SEXY” before promptly deleting it. Word had it that editor-in-chief Anna Wintour wasn’t too happy with revealing the April cover so early.