D3.js is a great tool for doing transformations on DOM-bound data, and can be used to create powerful visualizations, as you can see in the examples.

Here’s some extra sketches by Mike Bostock (author of D3) I found on the D3.js Google Group:

• Voronoi Tessellation
• Voronoi Tessellation (Interactive)
• Rainbow Colors
• Stroke Dasharray
• Moire Patterns
• Force-Directed States of America
• Date Ticks
• Venn Diagram using Opacity
• Line Tension
• External SVG
• Dynamic Node Tree