TweetGrid presents itself: TweetGrid is a powerful Twitter Search Dashboard that allows you to search for up to 9 different topics, events, converstations, hashtags, phrases, people, groups, etc in real-time. As new tweets are created, they are automatically updated in the grid. No need to refresh the page!
For more, see the FAQ. This appears to be a very useful tool for following multiple topics (as many as 9) in real-time!