TagCloud is an automated Folksonomy tool. Essentially, TagCloud searches any number of RSS feeds you specify, extracts keywords from the content and lists them according to prevalence within the RSS feeds.
As I <a href="http://blog.pietrosperoni.it/2005/04/12/technorati-tag-rss/">predicted</a>, a service that offers rss feed of technorati tag blog entries has appeared.
S. Rendle, and L. Schmidt-Thieme. Proceedings of the third ACM international conference on Web search and data mining, page 81--90. New York, NY, USA, ACM, (2010)