Comments: The brand promises "100% spill-proof drinkware," and, with the lid seated correctly, we did not have any spills. Holding the mug with one hand, you push a button, a little hatch opens, you drink your drink, you let go of the button, the hatch closes. The double-wall vacuum-insulated cup promises to keep hot drinks hot for 4 hours and cold drinks cold for 12 hours (how does it know the difference?, we wonder idly).

The mug fits in virtually all cup holders. While the plastic top is dishwasher-safe, the company recommends that you hand-wash the stainless steel cup (to avoid harsh detergent).

The cost savings are predicated on your skipping a daily stop at the coffee shop, which, the manufacturer says, will save as much as $2,000 a year. It also says coffee drinkers can save 23 pounds of paper cup waste each year by carrying a reusable mug (preferably Contigo's). Water drinkers will save billions and billions of plastic bottles (the actual number escapes us at the moment) by not purchasing bottled water.