New York City's famed Algonquin Hotel, Zagat-rated l'Absinthe Restaurant, and flashy Ruby Foo's on Times Square all are serving up tap water. The posh A.O.C. restaurant and wine bar in Los Angeles is adding tap water to its list of potables. And San Francisco's influential Slanted Door restaurant is going with plain ol' H2O too.

Why are more than 2,000 restaurants around the U.S. selling glasses of ordinary tap water for a buck this week?

It's called the TAP Project, and this is a nationwide effort supporting UNICEF and World Water Day.

Between March 16 and March 22, participating restaurants will serve tap water at $1 a glass. For every dollar raised, a child in a developing country will have clean drinking water for 40 days.

Search on the project's website to find restaurants near you. More are still being added.

If there isn't one in your town, you can also donate directly to the TAP project.

UNICEF's water sanitation work reaches out to the 425 million children around the world who don't have access to clean water. The TAP Project makes it easy to help right now at your local restaurant.