2014-05-28: TrueCrypt currently has security issues and is not recommended.
If you’re running GNU/Linux, dm-crypt with LUKS is the recommended encryption option.
Gentoo GNU/Linux maintains a guide for dm-crypt with LUKS.
Arch GNU/Linux maintains a guide to dm-crypt with LUKS. Also useable for Parabola GNU/Linux.
Apple, Google, and Microsoft are allegedly a part of PRISM. Their proprietary operating systems cannot be trusted to safeguard your personal information from the NSA. We have two free alternatives: GNU/Linux and BSD.
GNU/Linux has a much larger community to help you with the transition. It’s recommended that you begin your explorations by looking for a GNU/Linux distribution that suits your needs. Additionally the Free Software Foundation hosts a list of completely Free distributions.
Debian has a long tradition of software freedom. Contributors have to sign a social contract and adhere to the ethical manifesto. Strict inclusion guidelines make sure that only certified open source software gets packaged in the main repositories.
Fedora is a community edition that serve as the stable basis for enterprise ready GNU/Linux distributions with commercial support. Companies all over the world trust Red Hat Inc. because of their transparency throughout the whole development process.
Canonical’s Ubuntu is not recommended by PRISM Break because it contains Amazon ads and data leaks by default. GNU/Linux distributions based on Ubuntu are also currently not recommended due to several other reasons.
There is also a DuckDuckGo hidden service at 3g2upl4pq6kufc4m.onion for Tor users.
MetaGer is a SaaS by the German non-profit SUMA e.V. that provides you with anonymous meta search results.
Startpage is a SaaS hosted in the USA and the Netherlands that provides you with anonymous Google search and image results through a free proxy.