envirolink is a remarkable clearinghouse for more environmentally-related information and projects than any other site we know of.
The Intentional Communities web site is a great collection of information about current and planned large group living situations ranging from simple sharing of common spaces and occasional meals (co-housing) to shared-philosophy and shared spiritual path and even completely communal set-ups. It takes a village (nay, many villages) to save a planet.
The Rocky Mountain Institute has produced a wealth of useful information, much of it related to highly energy-efficient appliances. Their designs might make it possible for everyone on the planet to enjoy the benefits of a technologically advanced lifestyle without destroying the Earth. Their work on "hypercars" is particularly interesting.
The Millennial Foundation and their publication Distant Star explore the possibilities of ocean and space colonization as one possible path to sustainability (or at least alleviating the pressures of growth for a while). Of course, none of this means we don't have to promote family planning-- most problems can be addressed by multiple simultaneous solutions.
Real Goods Store is the general store of alternative energy products.
Earthships embody a liberating and refreshing approach to architecture-- Imagine living in a home you built yourself (largely from recycled materials) off the grid and practically mortgage free! The Environmental Building News is a great source of info about more conventional sustainable building materials and practices (aimed at builders and architects). A good page on Straw Bale Construction can be found at pcisys.
The Video Project is a clearinghouse for videos on the environment, social justice, and peace issues. If we limit our dialog to books and periodicals, we exclude the masses of people who either can't or don't read. We live in a videocracy. We are ruled, more and more, by thin people with good hair and straight teeth who can talk entertainingly with other talking heads. Today, taking the message to the streets means taking it to the tube. One possibility: start a video club, like a book club, with your friends and take turns buying videos to share with eachother... then loan them out or give them to the local library. Speaking of video, I recommend Michael Moore's movies and videos ("Roger and Me", "The Big One"). His other site is Dog Eat Dog Films.
The National Renewal Energy Laboratory Recent successes with hydrogen-producing solar cells (12% efficiency!) are truly inspiring. Now, there's an energy source for my future hypercar.
World Watch Institute publishes The State of the World annually in many languages. They have just about the best grip on the "world problematique" as any source on the planet.
Public Broadcasting System is about the only TV I ever watch and has lots of good history, science and news programs.
In radioland, National Public Radio air excellent news with "All Things Considered". NPR often airs stories from Pacifica Radio, telling the real news like no other organization I know of. Pacifica's web site has RealAudio streaming audio of their broadcasts, so I often start up a RealAudio window and listen to Pacifica News while web-surfing. NPR also includes wonderful analysis from Alternative Radio, hosted by David Barsamian.