David Petersen just contributed a great new plugin for Confluence: the Chart Plugin. You can now make simple charts from basic table data in pie, bar or line form.
Inserting markup like this:

||Party      ||Democrat ||Republican ||Independent ||
||Percentage | 40       | 40         | 20          |

Will create a graph like this:

Check out the plugin homepage for downloads and instructions.
There are all sorts of cool things that we could do with charts. And we’ve only scratched the surface of what’s possible. The source is available in the Dev Net Subversion repository so you can contribute improvements or fixes if you like. And there is a Jira project for the Chart Plugin, so if you find bugs or have feature requests, file them here.

Confluence Chart Plugin