By using the search functionality within a twitter stream, users can filter for:

By using the search functionality within a twitter stream, users can filter for: Tweets containing keywords and key phrases, Tweets from specific users, Tweets containing @mentions, Tweets from specific locations. The secret to using Twitter effectively is using the Twitter lists. Each Twitter list you create, gives you a different Twitter stream, customized to your liking. It will only include tweets sent out by those accounts you have added to the list