ThinkGeek :: Solar Powered Water Bottle Cap --- note from kelly - bought this for my husband and 12 year old son for 2012 christmas. They are awesome and I think they will like them for camping. but definitely check the bottles you have.
The hand-cranked GSI Outdoors Vortex Blender adds a touch of class to any campsite or tailgate party. Attached easily to any table or tailgate with its own handy C-clamp, the Vortex Blender cranks out smoothies, sauces and pancake batter.