Twitter CEO Dick Costolo announced that there is now an option for users to download an archive of all of their tweets. To download the tweets, go to the bottom of your Settings page. After you request an archive, Twitter will e-mail you a download link when it is ready. This is similar to the way that Facebook lets you extract your data. This option is being tested with a “small percentage” of users right now.
Go to Twitter settings. Scroll down to “Your Twitter Archive”. Download ALL your tweets. Even your first. DO IT. DO EEEEEET NOW!
— Psanta(@Psilosophy) December 16, 2012