Ridding the world of plastic bottles is quite the stylish endeavor.

The trendlet

We can thank S'well. The stainless-steel water bottle is as ubiquitous on yoga mats and spin bikes as it is in a Google cafeteria or at a TED Talk. Who knew being green could be so chic?

Since when?

The idea for a sleek, reusable water bottle came to Sarah Kauss, Harvard Business School graduate and New York entrepreneur, in 2009 when she was on a hiking trip with her mother. During the excursion, Kauss determined that the plastic water bottle she carried wasn't just sad, but also inadequate — it  was ugly and kept her water tepid at best.

Kauss decided to make her own bottle. She hired a design company and invested the bulk of her savings (in her previous life, she was an accountant). In 2010, Kauss launched the original ocean-blue-hued S'well, about a foot high with signature silver twist-off top.

Shortly after the launch, O, the Oprah Magazine, featured S'well on its O list. The San Francisco Museum of Modern Art and the Guggenheim started selling them in their gift shops. (Can you really get more exclusive than that?) Eventually, Crate & Barrel started stocking the bottles, as did Neiman Marcus, Nordstrom, and, finally, Starbucks.

These days, they are given away in swag bags at TED Talks and to folks who visit Google headquarters. And they come in lots of designs. Last month, S'well launched a selection of short, tumbler-size bottles — so your S'well bottle is now holiday-party-approved.

Can a water bottle really be that cool?

It can. They're a celeb favorite. Think:  Kaley Cuoco, Ellen DeGeneres. We see them carried by all the cool people walking through the city.

How much do they cost? Where can I get one?

They run from $35 to $42. You can get them at Neiman Marcus, Starbucks, and J.Crew.

So does Elizabeth have one?

Yep. Sue Pinto, owner of Rebel Yoga Studio in Chestnut Hill, turned me on to them, and I've been using mine during my workouts ever since. It really does keep the water ice-cold.