PCWorld: In an attempt to beef up security, Twitter is expanding users' ability to use HTTPS with the service. The HTTPS protocol encrypts data before it is transmitted. Twitterers can now change their settings so that they always use the more secure protocol when logging in. That should make it more difficult for others to steal their credentials when they access the site from a public Wi-Fi connection.
Twitter recommends that those who use third-party apps to connect to the service check to make sure those apps will also enable the use of HTTPS.