UV purifier....clear bottles......aeriate non potable water by shaking...hang in exposed sunlight 8+ hours

minnow trap....2 liter... cut off top, reverse cone section..add entrail for bait

micro scale solar desalinator...2 liter... cut off top cone section with non leaking cap installed..small amount of brackish or salt water in bottom of bottle...small catch cup (weighted)centered in bottle (a funnel that makes a contact seal with the rim of the catch cup helps keep the condensate from re vaporizing)...reverse cone section to bottle...add cool water to the reversed cone section to improve condensation rate...use pre warmed top section water for brackish source...make a dozen or so

chandelier...water filled clear bottles to focus/project small light source