In January, when the power shift in Egypt occurred, the Egyptian government made a point of "shutting down the Internet" which in this case meant directing telecom providers to stop their connections in and out of the country. The main reason was that social media networks like Facebook and Twitter were aiding in the organization of rallies against the government.
Fast forward to last week when an 8.9 earthquake (and the resulting tsunami) ravaged Japan. In a message sent Friday from the U.S. Embassy in Tokyo to U.S. citizen in Japan, the Embassy encouraged Americans "to continue your efforts to be in contact with your loved one(s) using SMS texting and other social media (e.g. Facebook, MySpace, Twitter, etc.) that your loved one(s) may use."
In fact, some people have given up Facebook for Lent so it's even impacting how some practice religion. Would you be able to make the sacrifice of not using a social network for 6 weeks? I think that some of my friends did not see me online for that long they might start checking hospitals.
As powerful as these networks have been at changing lives, let's not overlook the most important item of all. It gives you a reminder when it's Mom's birthday.