Searching - snapbird; plus download your archive of tweets
People have been able to search (albeit slowly) older tweets for a while now, using Snapbird.org
You can also request you complete archive of tweets (click on your name/icon top-right -> Settings -> Your Twitter archive) -- a while later you get an email with a link to where you can download a file containing everything you've done on Twitter.
~Andrew~
Biting the hand that feeds IT
