Oikos is run by some folks I used to work with when we were doing seminars together on energy-efficient housing.
They have since become a resource for quality information on green building and other innovative construction alternatives. http://oikos.com/index.lasso
Click http://oikos.com/resources/search.html to search for products
Here's just an example product I've mentioned before: A heat recovery system for showers: http://oikos.com/esb/42/gfx.html.