Taken from PC World Magazine, October 2011 Edition

When browsing the web, protect yourself by using HTTPS (Hypertext Transfer Protocol Secure) whenever possible. It encrypts the connection between your PC and the website you’re visiting.

Many site use HTTPS by default: When you purchase an item online or log in to a bank site, for instance, your browser will probably connect to the site via HTTPS automatically.  But you can enable HTTPS on Facebook, Gmail, and Twitter, as well.

To enable HTTPS on Facebook, log in to Facebook and click on the drop-down in the top-right corner, clock on Account Settings and then Security. Click on the Edit beside Secure Browsing and turn that feature on.

For Twitter, look for Settings.  In Gmail, click on the gear icon and select Mail Settings.