Firefox add-on does 'HTTPS Everywhere'
Well, everywhere possible
The Electronic Frontier Foundation and The Tor Project  have teamed up to offer a Firefox add-on that beefs up https on several major websites, including Google.com, Wikipedia, Twitter, Facebook, and PayPal.
Currently in beta, HTTPS Everywhere is designed to make encryption easier to use on sites offering at least partial SSL support. Google, for instance, still defaults to unencrypted search, but the EFF's add-on automatically takes you to the https incarnation.
"Many sites on the web offer some limited support for encryption over HTTPS, but make it difficult to use," says the EFF. "For instance, they may default to unencrypted HTTP, or fill encrypted pages with links that go back to the unencrypted site. The HTTPS Everywhere extension fixes these problems by rewriting all requests to these sites to HTTPS."
The code behind the add-on is based in part on the Strict Transport Security (STS) response header put together by the NoScript project. "HTTPS Everywhere aims to have a simpler user experience than NoScript, and to support complex rewriting rules that allow services like Google Search and Wikipedia to be redirected to HTTPS without breaking anything."
Google rolled out an https version  of its search engine late last month, announcing the move in the same blog post in which it admitted  that its Street View cars had been collecting payload data from unsecured Wi-Fi networks across the planet. Normally, to use SSL-ed Google Search, you must specifically visit https://www.google.com (note the "s").
After installing the HTTPS Everywhere add-on, if you visit http://www.google.com (no "s"), you will automatically be taken to the SSL version. The same is true for sites such as Wikipedia, Twitter, Facebook, The New York Times, The Washington Post, Paypal, the privacy-minded search engine Ixquick, and, well, EFF and Tor. And once you're onto secure versions of these sites, the plug-in attempts to keep your traffic within these sites encrypted as you move from page to page.