The logo is copyright © 2011 by David W. Kennedy and is licensed under Creative Commons BY-NC-SA 2.0 Generic.
The logo uses an image of a water droplet on a leaf that is copyright © 2009 by Stephen Begin, licensed under Creative Commons BY-NC-SA 2.0 Generic and was found here.
The image of Chicago from Lake Michigan is copyright © 2007 by Blondie5000 (Angela), licensed under Creative Commons BY-NC-ND 2.0 Generic and was found here.