If I were in your position, I think I'd have went to ham radio and probably a police scanner first. I know the ham community is pretty serious about helping with disaster response, and it should be high SNR. Good reason to make sure hardware to at least receive that stuff is handy.
To follow a recent disaster involving massive quantities of oil, what I found worked best was a IRC channel loosely connected to a blog on the topic. With a few thousand people on such a channel, the info can be pretty good (like, play-by-play discussion of what each of a dozen undersea robots is doing) while the noise is not as horrific as a fad that every celebrity and anyone who cares about every celebrity, or wants to be one, is busy blabbering on.
With the addition of a collaboratively written blog or wiki, you don't have to be on the channel 24/7 to keep well-informed. This blew all the mainstream coverage out of the er, water.
And yeah, identi.ca if it has to do with free software, again a smaller community with a better SNR.