Care2 is simple: One person can make a difference.

http://www.care2.com/ 

Truly one of my more frequented sites, especially for the petitions! 

It is an environmental portal for:

• healthy living tips
• eco-directory
• eCards - generate donations to the environment
• Free photo sharing
• Free webmail

This is one of the few newsletters I go out of my way to review each time I receive it.