A sturdy bottle will last years - and that's ecological. We carry a range of SIGG aluminum bottles, Nalgene and Camelbak plastic bottles and many others. Thanks to the recent upset regarding liner materials, bottles are now safer than ever - no high profile bottle maker can afford to use suspicious liner materials any more..
Many back packs have a place for a hydration bladder.
Mountain bikers, backpackers and paddlers have been using them for years in situations where a bottle is too small or inconvenient. Hydration bags make hydration easy and virtually hands-free. The easier it is to take a sip, the better hydrated you tend to stay. Hydration bags are als very light in comparison to their capacity.