I ran across a few interesting data visualization products: some open-source, some commercial:

• http://www.tableausoftware.com/ (commercial)
• http://code.google.com/p/birdeye/ (open-source) — ActionScript
  • BirdEye is a community project to advance the design and development of a comprehensive open source information visualization and visual analytics library for Adobe Flex. The actionscript-based library enables users to create multi-dimensional data visualization interfaces for the analysis and presentation of information. The project is based on development and the integration/adoption of related open source libraries (see credits and attributions).
• http://manyeyes.alphaworks.ibm.com/manyeyes/page/Visualization_Options.html — you submit the data and they process it on their servers. Good set of visualization tools, but data becomes public.
• http://www.simile-widgets.org/timeline/ (open-source) — JavaScript
• http://www.dipity.com (commercial)