Hi all,
We created a component and a Plugin to be able to use OpencCalais in Joomla.
Before, you needed to have the Flexicontent component (http://www.flexicontent.org).
It's very easy to use, you can find the extensions on: http://www.joomlafact.com/joomla-extensions/components/jf-opencalais.html
and http://www.joomlafact.com/joomla-extensions/plugins/jf-flexiopencalais.html
This component is used on http://www.startupsmart.com.au/
Don't hesitate to contact us if you want more info.