I own 4 of these Klean Kanteen bottles - 2 27oz and 2 40oz bottles - and I use them everywhere - on runs, on trails, in the car, etc.
Finally an eco-friendly choice...but it gets better. Unlike plastic bottles (even the Nalgene and "taste-free" eco-plastic bottles), this is the only water bottle or bag that doesn't leach a nasty taste.
Plus, even Nalgene bottles have been shown to release carcinogens. To test, just put the bottle out in the sun for a day and drink. Yuk!
While plastics are porous (or micro-porous), this metal is not - meaning no nasty bacteria will grow on the bottle. Watch out - other plastics are treated with nasty chemicals to be anti-bacterial.
Plus these are super easy to clean - just add diluted vingear, shake, and rinse.
And the cap is awesome. It's very tight and has a great loop for extra security, clips, or just to slide a finger through.
They're light too!
Plus, the never wear out! What's not to like?