United States Environmental Protection Agency: The US EPA has many online resources for a variety of audiences, as well as an email newsletter for on-going updates.

Royal Society of Chemistry: This European professional organization for chemists has some interesting articles on drinking water, organic farming, and other environmental concerns.

E Magazine: E Magazine is dedicated exclusively to environmental issues, and their web presence and free weekly email newsletter provide valuable sustainability information.

Ideal Bite: Sign up for this green tip-a-day service to receive ongoing conservation ideas by email, five days a week.

Recycling Revolution: A great instructional source on recycling.

RecycleMania: Home of a recycling competition between universities. The University of Tulsa participates, thanks to the efforts of USC.

Oklahoma Sustainability Network: This organization is dedicated to providing a network for environmentally-minded citizens and improving Oklahoma's environmental efforts.