The new demos are truly impressive. My browser can now do things I didn't imagine.
We've redesigned the site and added the ability to interact with Demonstrations directly in your browser--no more downloading files or switching between applications.http://www.wolfram.com/ http://www.wolfram.com/mathematica/ http://demonstrations.wolfram.com/
With the Wolfram Demonstrations Project:
* Explore concepts through nearly 7,000 interactive examples covering engineering, math, physics, biology, finance, sociology, astronomy, music, art, and many more areas, even fun games and puzzles
* Get ideas for projects, and use source code to jump start your work
* Share your ideas with a global community of hundreds of thousands
You can re-acquaint yourself with the project by watching this brief video:
Explore the new Wolfram Demonstrations Project and how it can help you. Join the global community of over 400,000 users every month!
The Wolfram Team
PS: Have you looked at Mathematica 8 lately? The world´s most powerful computation system now features free-form linguistic input, getting you started instantly, without any knowledge of syntax: http://www.wolfram.com/mathematica/