Building your own window farm
I saw an article on Lifehacker, which talked about a project called http://our.windowfarms.org/
Window Farms focuses on helping households create their own “Micro farms” by utilising window space. The hydroponic system can churn out a salad per week.
The tutorials take you through the process of measuring your window, calculating how many ‘pods’ to chain together, how to create the hydroponic solution, selecting pumps, etc.
A good place to start learning is with a basic reservoir system window farm, this article has a PDF explaining the entire process (http://our.windowfarms.org/2009/07/30/how-to-build-a-reservoir-system-window-farm/), but I recommend exploring all of http://our.windowfarms.org/ to see what other ideas are there.
If you have spare space and some free time, why not try constructing one yourself, not having a backyard isn’t an excuse any more!