[Someone]

Background info: http://en.wikipedia.org/wiki/Air_well_(condenser)

The device in India shown there produces 15 liters of water per square meter per year. The surface area of a bottle is, say, 500 square cm, or 1/20 of a square meter. That would produce about a liter in a year.

http://www.iimahd.ernet.in/publications/data/2005-01-05gshar... talks of 0.042 liter per square meter per day, in extreme.y high humidity.

Clearly, some efficiency gains are needed w.r.t. those designs to effectively make the claim "water bottle tha fills itself". Whether that is possible, I don't know.

[lloeki]

This instantly reminds me of the fictitious windtraps in Dune (mistakenly used as powerplants starting with the second game)

[0]: http://dune.wikia.com/wiki/Windtrap

[novaleaf]

if you read further down in the wikipedia article, it shows zibold's collector which produced about 0.9 liters/square-meter/day

just pointing out that efficiency may be better than what you are estimating.

[Someone]

It may be, yes, but Wikipedia isn't convinced. Even further down, it states:

"Zibold's condenser had apparently performed reasonably well, but in fact his exact results are not at all clear, and it is possible that the collector was intercepting fog, which added significantly to the yield.[10] If Zibold's condenser worked at all, this was probably due to fact that a few stones near the surface of the mound were able to lose heat at night while being thermally isolated from the ground; however, it could never have produced the yield that Zibold envisaged"

That made me look for more recent data. That PDF from 2005 was the best I could find.