It's not very environmentally friendly, but if you're really concerned
with safety, re-using evian type water bottles isn't a good idea.

http://www.bottledwater.org/

Hi, Stu, I guess you appreciate the irony of talking about
environmental friendliness and disposable water bottles in the same
breath?

Travelers who want to stay healthy AND be green should consider
traveling with a personal, refillable stainless steel bottle, unless,
of course, tap water quality is an issue at your destination. If
you're on a cruise, it's not an issue, except when you plan to be off
ship longer than your supply will last in a place where water quality
is suspect--then, you can simply buy disposable water bottles to fill
the gap.

I like my Klean Kanteen (use it almost daily in addition to
traveling), but a friend said the new CamelBak version has features
some might consider improvements. (Not to confuse things--the CamelBak
water bottle is not the same thing Rosalie mentioned, which is
CamelBak's "hands free" hydration system, a wonderful thing for
outdoors pursuits, overkill for most cruisers.)

Diana Ball
Austin ,TX