That's a thread going on at CJR.org on how journalists should use Twitter:

http://www.cjr.org/news_meeting/how_should_journalists_use_twi.php

Click through and read the comments if you're interested in this stuff.

As for me, use Twitter for an early-warning system and a possible way to identify sources and witnesses. But don't use it as a crutch or take everything on it as the gospel truth. Verify.

Another thing I find is that in some ways, look for what people are not saying. Twitter is a social medium, and I think that tends to skew the conversation.

Think critically about that as you try to glean insight from your stream of tweets.