Just a minor sidebar, at Johan's suggestion I've released wicket-googlecharts into the wicket-stuff project. I played with the build system a bit to make it work with maven and I think I did it right, but my maven experience is limited. License is currently discretionary, though if I really had to pick one I'd probably go with either ASL2 or BSD.
Warning: anything that isn't tested by the test page in the project is completely theoretical and untested. This means things like scatter plots, color fills, etc are all up in the air. I'll probably get around to stabilizing functionality eventually, but for now it can just float. Hopefully someone will find this useful! Daniel (original article: http://www.codecommit.com/blog/java/a-wicket-api-for-google-charts)
