twitter for journalists
In addition to hash tags and lists (which are essentially special forms of searches) Twitter provides two different ways of searching by keyword, username, geography, dates and more. Searches can be as complex as you need them to be!
For a journalist covering a community or a beat, you'll probably want to craft some custom searches that turn up useful sources and observations. You can save these searches and check them daily, either on twitter.com or in your favorite client.
Using Twitter's simple search, click Save this Search to return to it easily in the future.
To revisit your saved searches later, just click the Searches tab on your Twitter homepage profile. If you're using a Twitter client, you'll find you'll find your saved searches elsewhere in the interface. If you're using a multi-column client like TweetDeck or Hootsuite, you can set up a saved search to appear in a permanent "column" (caveat for HootSuite users - only searches created from within Hootsuite can be seen - official saved searches are invisible to Hootsuite).