Google Green is a site about how Google is working to decrease it's impact on the environment. There is some great information on there about it's initiatives like goats instead of lawnmowers, wind power, efficiency, and more.
One of the really interesting pages on the site is the "Story of Send" which gives you a behind-the-scenes look at what happens to an email after you hit send through animations, videos, and photos.
It details how data travels from your device, through the internet service provider, to Google's data centers and then onward. It explains how they filter for spam and scan for viruses and even how they are minimizing their impact on the environment.
There are videos and photos, along with descriptions, on the site.
This is a great resource for students to learn more about the internet and data, as well as environmental issues.
Check it out: http://www.google.com/green/storyofsend/desktop/