There are lots of online social networking sites that are solely focused on green issues. They're a wonderful way to network without having to sort through to the green stuff.

13. WiserEarth

WiserEarth has been around for a couple years now, and has grown ever larger with a loyal user base. The site facilitates an easy way for people to network with groups and organizations, businesses, and fellow green thinkers. It is the LinkedIn of the green world, and then some.

14. MakeMeSustainable

MakeMeSustainable is a bit like Facebook in terms of friendly social networking, but with the ability to track and offset your carbon footprint. It means that social networking can be directly linked to your activism for sustainability. You get the best of two worlds.

15. Create your own green social network at Ning

If you have an idea for a green social network that doesn't fit within the bounds of any of these popular sites, build your own! Ning is a resource that lets you create your own network. Search networks that already exist, join up with any that strike your fancy, and create your own to suit your individual niche!