Google Sketchup

SketchUp is a simple but powerful tool for quickly and easily creating, viewing and modifying your 3D ideas. Click on a shape and push or pull it to create your desired 3D geometry. Experiment with color and texture directly on your model. Real-time shadow casting lets you see exactly where the sun falls as you model. Select from thousands of pre-drawn components to save time drawing.

http://sketchup.google.com/

Time Line

Timeline is a DHTML-based AJAXy widget for visualizing time-based events. It is like Google Maps for time-based information.

http://simile.mit.edu/timeline/