Interesting article from the NYT on Egypt's Internet shutdown - doubly interesting for what it says about cloud services.
Essentially they stopped the packet flow in and out of the country - meaning that all these services that existed outside of Egypt, eg Windows Live, Gmail, Google Docs, Facebook, Twitter and so on stopped working.
Services inside of Egypt continued to work, so that universities were able to update their web pages but had no means of communicating with those of their students (most of them) who used one of the big three webmail providers.
Now let's think about what happened in a recent natural disaster - the Queensland floods. Both because a reasonable chunk of the infrastructure kept working and Australia is a nation of self-reliant resilient smartphone addicts, Facebook remained accessible even though domestic power was off and the old POTS lines (and hence ADSL) washed out.
The consequence was that it became a powerful tool in communicating with people and organising relief efforts.
If of course the 3G infrastructure and its external connections had died totally, all the smartphones would have turned into useless lumps of silicon and plastic.
And that is the lesson of the Egyptian experience for disaster management. The internet can go away at an infrastructure level cutting off access. Cloud based services continue to run because they are 'out there'. When planning new infrastructure in disaster prone areas physical resilience to maintain connectivity should be an important consideration, as should having standby equipment including satellite uplinks to get a limited service back running. Even if people can't call each other having the ability to post and receive messages allows people to communicate with loved ones and self organise