Avoiding Big Brother

"Phil Zimmermann's Silent Circle, which halted its secure mail service shortly after Lavabit, has released a messaging application for Android devices that encrypts and securely erases messages and files. The application, called Silent Text, lets users specify a time period for which the receiver can view a message before it is erased. It also keeps the keys used to encrypt and decrypt content on the user's device, which protects the company from law enforcement requests for the keys." Seems similar to pieces of the Guardian Project.