Tails is a Linux distribution that offers internet privacy by default, and comes as a live CD or live USB.
So you would insert the Live USB drive, restart the computer, and it would startup the Tails Linux Operating Sustem. You can encrypt any files you create with built-in tools, and any internet traffic is anonymised. When you’re done, shut down and remove the USB drive.
The concept is fantastic! There are far too many uses to list – from the noble and important goals of safeguarding communications within a repressive government, to simply protecting your privacy when using public WiFi (e.g. At a hotel, Starbucks or McDonalds).
It’s only version 0.10 at the moment (meaning there is a lot of work still to be done), but I’ll be following this closely. Check out the various ways you can support this project.
Technical Stuff: Astute readers will correctly note that you’re still vulnerable to hardware intrusions like keyloggers if you use untrusted hardware. Regardless, some protection (e.g. Tor network) of your activity is better than nothing. There are also various methods of avoiding keyloggers if you suspect hardware tampering – like using on-screen keyboards (incidentally, Tails ships with one).
The other concern is whether one can trust the Tails developers. To each their own.