With almost ten thousand files uploaded and over twenty two thousand pages, I encourage anyone with an interest in appropriate technologies for local solutions to various challenges to look at Appropedia, http://www.appropedia.org/Welcome_to_Appropedia.
In their own words - "Appropedia is the site for collaborative solutions in sustainability, poverty reduction and international development through the use of sound principles and appropriate technology and the sharing of wisdom and project information. It is a wiki, a type of website which allows anyone to add, remove, or edit content. Registration is encouraged but not required for contributors.
Appropedia has been described as an "appropriate technology wiki," but it is much broader than that - it is a green wiki, and a wiki for all matters of international development and aid. But most importantly, Appropedia is an open site for stakeholders to come together to find, create and improve scalable and adaptable solutions. For more about our motivation, see Appropedia:Mission."
Have a look!