How about an insulated, glass, bamboo water bottle? Glass is obviously one of the healthiest choices because you don't have to worry about stuff leaching into it, and why not sustainable bamboo to cushion it in a fashionable way? Only caveat, this bottle is heavier than the stainless ones, but so worth it! http://www.bamboobottleco.com
And while you're at it, try some Runa Guayusa tea, a new tea that provides antioxidants and a little pick up without the jitters of coffee, PLUS it's fair trade: http://www.runa.org/home.aspx
