Did a search here and didn't find this, so I thought I would add it. Seems simple to build, but I'm not sure about how much volume you'd have for output.
http://www.solaqua.com/solstilbas.html
Still a neat idea, though.
Survival manuals have been teaching this technique for gathering Dew water for centuries.. Its all fine and dandy, but $490 for a fiberglass container with food safe lining and some PVC legs? And You have to purchase glass locally. Seems a bit steep doesn't it? Plus I bet that it becomes a perfect environment for bacteria growth. so yeah you water is pure, but its flowing down an open trough next to a breeding hive of spores and god knows what else that was in the water you put in, and now sitting in a nice warm moist environment. Get the right parasites and then might be able to literally crawl over the barrier.
Yes it will work, but you could probably build something just as good out of a a piece of glass, and animal trough and a bit of food safe pipe cut in half and some waterproof caulk... for way under $100. You can get a good Berkey filter for under $300. Why would you spend money on this? And 1.5 gallons in the summer. 3/4 gallon in the winter? Yeah, that might handle drinking water. Don't wash the dishes or yourself. Its a great survival tactic, probably not so great for day to day living...