The link that bugsy gave is an American manufacturer.
It does not say how they work it but it is probably a refrigeration
system or a peltier effect system similar to thos car coolers you can buy.
They have units with solar cells, but it is fine for field use but
I can't see it being a goer elsewhere.
Back to the drawing board.

Water from air is no new thing. In Crimia there exist large piles of dark rocks on a concrete bases. The idea being that the rocks radiate their heat and water condenses on them and is collected on the base.I imagine that one would need a humid climate

The windmill is interesting in that it seems to harness vertical air movements (such as hot air rising during the day) as well as the conventional horizontal ones (wind). I guess it uses a heat pump (refrigerator) to extract water vapour from the air. Were the technology applied on a broad scale, it is likely to adversely affect cloud formation and rainfall – i.e. less. Already large wind farms have been observed to alter local climate through their effects on wind – so renewable energy is a little trickier than one may think ( see http://www.newscientist.com/article.ns?id=dn6608 ). I think the mill would work, but it is not that useful.

I had wondered if perhaps the design was centred around a stirling engine rather than a gas refridgerant system. Fascinating concept - it will be interesting to watch.

Well it as it generates kinetic energy from wind, it might as well use that to compress air, and work as fridge. But on the other hand, when you compress air, you get water out from it. No conversion to electricity is needed. I think that would rice it's efficiency dramatically.

And about the design, i would draw it as something like this:
http://www.androsgreece.gr/IMAGES/TECHNOLOGY/ftera.jpg
but with the 'wings' in horizontal level, generating lift -> reducing friction. Well this is just guess, but that would work in any direction at least.

Photos of vertical wind mills I have seen look a bit like an elongated
egg beater held vertical. Vertical windmills are quite commom I gather
but they need higher wind speeds to get them started.
The idea of not generating electricity and driving it directly must
improve the efficiency provided it can stand varying speed.
Systems like this might be practical for drinking water and cooking,
but could it produce anything like what we currently use ?

It might get far too big.