Are there lightweight solar stills that work?
For a mere $3500 plus the trouble of lugging around another 45 lbs or so of equipment you could take a 1.5gal/hr electric water maker and an 80W solar panel to power it. That same 45 lbs amounts to about 5.5 gallons of fresh water, so depending on how much water it would save you from carrying it might be a net savings, weight-wise, but probably not by much unless this is a seriously long trek.
