Interactive Forces of Nature

I'm a big National Geographic fan. I've subscribed to their magazine in the past (and will again in the future when I've actually got free time to read it) and currently receive a few e-newsletters in my inbox. The website is usually well done and there's always lot's to see and do.
Here are a few fun NG interactive pages:
Lightning - Make lightning strike and learn about how it's produced
Avalanche - Create and avalanche and learn about the different types
Forces of Nature - Create a tornado, volcano, hurricane and earthquake and learn about the different types
If you're ever bored, just type 'interactive' into the search bar on the National Geographic homepage. Time well wasted - way more fun than writing papers over Reading Week...