Below are some sites that I've come across and thought were interesting. Perhaps you will too!

• Desert Research Institute - Excellence in Environmental Research
• The HubbleSite - Amazing Photos from our Favorite Telescope in Space
  
• The Gateway to Astronaut Photography of Earth
  
• Western Regional Climate Center
• Google Moon - Apollo and other Lunar Landing Sites
• NOVA | The Elegant Universe | Watch the Program | PBS
• World Atlas - all the Facts & Figures about Countries, Continents, Astronomy and more
  
• Earthview - View Select Places on Earth from Satellite
• FAQ about the Meaning of Life and other Philosophical Questions
  
• Grand Illusions Toy Shop - New and Amazing Toys
  
• Molecular Expressions: Science, Optics and You - Secret Worlds: The Universe Within
• Internet Traffic Report - Monitor Current Traffic and Use
  
• Relativity Tutorial - Space/Time Diagrams
• MathPages: Physics Explanations and Stuff
  
• Science & Technology at Scientific American.com: 15 Answers to Creationist Nonsense