Two factor authentication is one of the safest measure to further secure your online credentials. Google, Apple iTunes, LastPass, Dropbox, and a few other online services have provided this in the past (by either having a Google Authenticator app that generates random codes, or using a text message to your phone).
There is nothing scarier than having someone hacked into your Twitter account, especially if you have gained followers and some kind of reputations on Twitter. Recently, Twitter has launched an update that enables two factor authentication on your Twitter account.
How to enable two factor authentication on your Twitter account
 Go to Twitter.com and your Account Settings (through the Gear icons on the top right).
 Tick the “Require a verification code when I sign in” box under the Account Security
Add a phone to your Twitter account if you haven’t. If you have, you should see this instead:
Tick the box and follow the next sets of instructions to enable two factor authentication on Twitter.
Twitter will now enforce a second verification to your phone to ensure that you are the only who can access your Twitter account. When someone manages to get your Twitter’s password, they will be helpless to wreak havoc because they don’t have your phone (well, unless if it’s the same thief….)
Source: Twitter’s blog