Tag-Cloud of all Tags

Hello

One fact why I decided to use elgg was the tagging function. For me it is essential to tag almost every content. 

Now I'd like to have a tagcloud showing all tags (size based on relevance) on the main site as well as on other sites like riverdashboard, profile ... 

 

Is there a possibility / plugin to do so ? Or Is anyone interested in developing a plugin like this ?