Twitter began as an SMS service starting today, "If you add your phone to Twitter, you can update anywhere, anytime by simply sending us a text message! Once your phone is verified, you can start sending (and in many countries start receiving) updates instantly! Depending on where you are, you may have a local number. You can send a text message to any of these numbers and it will post directly to your Twitter profile, and be sent to all of your followers, explains Twitter.
"we continue to build out SMS capability because we recognize the importance and value of making our service available to every person on the planet. No matter what device people use -- from the most advanced smartphone to the simplest feature phone -- people around the world should be able to send and read Tweets," the company stated.
Twitter partnered with the two largest satellite operators, Iridium and Thuraya, to give their subscribers access to Twitter SMS. Now, even if phone lines and the Internet are inaccessible -- for example, in a war zone or after a natural disaster -- people will be able to share news and stay informed via Twitter.
Twitter work with many carriers to support SMS around the world. If your carrier does not currently support Twitter SMS, you can still Tweet. Just use one of the long codes.
Twitter currently support 2-way (sending and receiving) Twitter SMS via short codes for the below listed countries.
Here's a full list of mobile carriers and satellite providers that support Twitter SMS.