You mention like-minded neighbors... even if everyone in your community is like-minded, your community property boundary touches properties owned by people who may not share your vision or ideals. Then you need to create a buffer zone around your community. But even still, and especially significant for communities that want to do farming, property beyond your control can do things that directly affect water flows into your property.

There are some eco village efforts going on around the world. The Tamera group in Portugal is fairly famous (and mentioned in the article), but it tends to draw a lot of attention due to it's _almost_ mandatory practice of non-monogamy. (And I challenge you to look through their photos and imagine being expected to have sex with some number of the other community members :P ).

Costa Rica seems to attract very eco-minded community efforts, and in fact much of their tourism is eco-related. You might find something interesting there.