The cool cat at //engtech has created a nifty work-around for edublogses and other WPMU sites to generate a “tag cloud” of most used categories in your blog.
Tag Cloud Generator for WordPress.com
http://engtech.wordpress.com/tools/wordpress/tag_cloud_generator_for_wordpress/
Here are the results here–
AI/AN Alaska blogging blogginess edublogs.org in process organizational culture public draft sciencing Teachers Uncategorized
Created by WordPress.com Tag Cloud Generator by //engtech