This is from the well done website of The Princess Gardens a community garden in Berlin. Thanks to Google translation and Google Reader we can read about the garden via an RSS feed.
Note the top watered planter boxes. A unique feature of this garden is portability. It is a mobile community garden.
I do not know of any community garden in the entire New York Metro area that grows in anything other than dirt. To the best of my knowledge, all are locked into the ground.I'm guessing that the original use of these cool looking planter boxes was for some type of industrial storage (or are they milk boxes) and that they are not watertight. Incidentally, it looks like their height would help to enable physically handicapped gardeners.
To further enhance productivity and portability, these boxes could be easily converted to sub-irrigated planters (SIPs) using a sheet plastic liner and inverted nursery trays to create sub-irrigation reservoirs and sub-aeration chambers. See here and here.
My belief is that productivity would be increased in the range of 50% based on user reports with other SIPs, such as the EarthBox, Tomato Success Kit, Garden Patch Grow Box and DIY versions made from tote boxes and utility buckets.