Could Twitter have helped?

Follow this scenario, and then I'll explain. A friend of mine, whom I met in Second Life has been unable to connect via her gaming computer, so her only means of contact with friends from SL is through her parents' laptop using standard instant messaging clients (Yahoo, AIM, GTalk, MSN, etc). She managed to IM me, and asked that I do her a favor. She asked that I relay a message to some of her friends from Second Life. I did, and traded some screennames between her SL friends and her, and all was well.

This got me thinking. Remember Hurricane Katrina? Remember how hard it was to locate people when phonelines, internet connections, TV, Radio stations were all severed in the gulf? I remember learning one interesting fact that sticks with me to this day. SMS or "text messages" were more likely to be received than regular cell-phone calls. That's because SMS, short for "short messaging service" works in a queue system, so they could be stored on the network until there was available bandwidth to send them. So, all of this makes me wonder:

If Twitter was around during Hurricane Katrina, and families and friends were already connected, how much of an impact would it have had?

Think about it! Families would have been connected. A wife would have known what her husband was doing. Sons and daughters could check up on parents or grandparents. Distant relatives could have heard the news of the hurricane and quickly set up a "track Katrina" message. And the list of possibilities goes on!

After thinking about it, I made sure my brothers, Mom, grandparents, and any other emergency contact I have, all had my Twitter address saved as a bookmark. Some of them don't carry cell phones yet, or don't regularly use text messages, so it wasn't sensible for them to make an account (yet), but it's definitely a start.

So I ask...could Twitter and apps like it, have helped (and will they help in the future)?