Concord, Massachusetts bans plastic water bottles writes:

Cities across the country have already worked towards banning plastic bags, and now Concord, Massachusetts has become one of the very first communities to ditch the single-use plastic bottle. The result of a three-year effort by local activists and an effective Ban the Bottle campaign, the new bylaw would make it illegal to sell non-sparkling, unflavored liquids in single-serving polyethylene terephthalate (PET) bottles of 1 liter or less. With exceptions for emergencies, a first offense will garner a warning, the second infraction incurs a $25 fine, and the third transgression earns a $50 fine. Concord’s Health Division is in charge of enforcing the ban starting the first of this year.

(emphasis mine.)

So, this ban doesn't touch soda, or gallons of water, or large-ish bottles of water.  Just the little ones -- like those tiny, part-of-a-serving bottles that are barely even worth drinking.

According to Ban the Bottle, single-serve plastic bottles take 17 million barrels of oil a year to produce, enough fuel to power 1.3 million cars a year. In 2007, Americans used 50 billion bottles, recycling only 23% of that amount. In 2010, the EPA estimated that the US generated 31 million tons of non biodegradable plastic waste. Banning plastic bottles in cities across the country could go a long way to reducing our petroleum footprint.

Altogether, this sounds like an awesome plan to me. points out the criticism, though:

Some critics of the ban question the usefulness of the law, observing that those who want to buy single-use bottles can travel a short distance to neighboring cities to purchase them. Some businesses have also taken advantage of a loophole by selling 20 oz bottles, since the legislation only focuses on sizes 1 liter or less. Even so, it is encouraging to see a community make strides towards reducing its impact on the environment and help keep its citizens hydrated and healthy.

Reasons this criticism is nonsense:  Virtually everyone will choose to buy larger bottles or drink tap water rather than drive to another town when they're feeling like an impulse-buy of water.  Furthermore, most people don't stock up on bottled water in tiny, tiny containers.  Also, selling larger bottles isn't getting around the law, it's the intended effect.  That way, any given individual wastes substantially less plastic per unit of water consumed.

I think this is a great law, and I hope it spreads.