Tapwater The mayors of New York and San Francisco are pushing a radical, bold new idea: It's okay to drink the tap water.

NYC Mayor Mike Bloomberg is defending his city's $700,000 ad buy promoting its tap water, saying that drinking more water can improve residents' health:

"If you can get [people] to drink a couple glasses more of water and a couple of fewer drinks of sweetened drinks, you could make a big difference in the biggest health threat that we see in this city today - and that's obesity," Bloomberg explained.

In San Fran, Mayor Gavin Newsom has just prohibited city agencies from buying bottled water for their workers -- which had been costing the city $500,000 a year.

As the San Francisco Chronicle notes, this isn't the first instance of its kind:

In 2005, Los Angeles Mayor Antonio Villaraigosa ordered city agencies to stop buying bottled water for employees after the media reported that the city had spent nearly $90,000 on it. At the same time, the city water agency was financing a $1 million ad campaign praising the virtues of what came out of the tap.

In many places, it isn't just that tap water is as good as bottled water -- the stuff coming out of the faucet is often better than the $2.00 bottle at the store. Just ask Cleveland.