A Curious Tale of a Loss of E-Mail Privacy

In Forbes:  An interview with Silent Circle co-founder Phil Zimmermann.   Had not heard of the company.   The company deleted its secure email service this past Friday.  Are there other options for encrypted email that can prevent external entities, like the government, from demanding and getting  their disclosure?  From their site:  " ... we have reconsidered this position. We've been thinking about this for some time, whether it was a good idea at all. Yesterday, another secure email provider, Lavabit, shut down their system less they "be complicit in crimes against the American people." We see the writing on the wall, and we have decided that it is best for us to shut down Silent Mail. We have not received subpoenas, warrants, security letters, or anything else by any government, and this is why we are acting now. ... "