Robin Good: One of the most effective and popular methods to stay abreast of a topic area or to discover new stories about an issue is the use "hashtags" for Twitter seaches.
Here is a bunch of tools that make it easy for you to monitor and search, one or multiple Twitter hashtags on your preferred topics.
Useful. Resourceful. 7/10
Tools list: http://www.searchenginepeople.com/blog/best-tools-to-summarize-twitter-hashtags.html
Via Robin Good