Naturally, your smartphone and social media apps of choice will work fine for updating your Facebook, Twitter, YouTube, and other sharing outlets. However, you can't count on a working wireless Internet connection during times of turmoil--we're seeing more and more governments cut the national cord once things get crazy. (You might want to print out How To Get Internet Access When Your Government Shuts It Down and keep it handy, just in case.) That doesn't mean your cellular network won't work, however. Even if your cellular and landline Internet access gets cut, you can still use voice service and SMS to take care of a few basic tasks.
You can start managing your Twitter account via SMS by texting the word START to your appropriate country code (listed here), then sending your user name, and then your password, and then the word "OK" to enable your account for SMS. You can also receive updates from selected users, follow new users, check profile information, and other basic Twitter functions via SMS code--check their SMS Commands page for the complete list.
Even if you don't want to use SMS, you might still be able to use your voice to tweet--during the Egypt uprising, Google hacked together a voice-to-Twitter service that used Google's speech recognition tech to post tweets automatically hash-tagged #egypt.
Facebook also has a surprising amount of SMS-friendly features, even though items shared on Facebook aren't as bite-sized as the stuff shared on Twitter. You start by activating a phone in the Mobile settings page. Once activated, you can update your status, post messages, and do a few other basic actions.