I found a bit about windowfarms about 6 months ago and had a small input about one of the toys I made. It is an "opensource" hydroponic window garden? design experiment and it has gone worldwide.
It started in Brooklyn
They now sell insanely priced kits in the USA so that people can do this themselves http://www.windowfarms.org/kits
However, I think it can be a really cool idea and should be expanded. I think the concept could also be used to keep seedlings watered in an ordinary greenhouse with normal soil or seed starter too.
A lady in texas has used some of my old pulser pump stuff to design her much cheaper DIY system.
I also put on a video to show that the airlift can be much much faster that what they show even with a cheap aquarium pump and much cheaper connections. (Perhaps you do not need fast water flow)
http://www.youtube.com/watch?v=TpfHRViress
I was thinking about how this could be expanded to poor countries and did the "biopowered water pump".
(Not everybody has electricity!) The biopowered pump just uses the gas produced from fermenting kitchen or garden waste or fermenting beer or wine to pump the water. My first one (that did not make it to video) was powered by bakers yeast and a cup of sugar. The one I show was powered by ground up morning glory, potato skins, and moldy bread.
There are 2 videos for it http://www.youtube.com/watch?v=-y1p2pZaYTM
and http://www.youtube.com/watch?v=G6pfE_IxVgQ (which is the same thing powered by an aquarium air pump. This shows the fill and empty cycle pretty good.
Would anyone like to join in,
either doing windowfarms or in trying out the waste powered pump? Or expanding it to cover greenhouse "normal" plants. In parts of Africa, they use a high "spiral" garden to grow veg. It might be productive to have a "biopowered pump" circulating compost tea from bottom to top with that system. It could be weed powered.
The fermentation process probably kills the weed and its seeds.
The bio powered pump is also on instructables at
http://www.instructables.com/id/Build-a-fermentation-fueled-water-pump/
It is community commons with commercial builds allowed. (Which means that you can market kits if you want). And charge insane prices too!
Brian