Protecting your privacy
Bits of Freedom has started a wiki (in Dutch) about measures you can take to protect your privacy. It currently contains information about secure email, file encryption and blocking of tracking and other mechanisms used by advertisement providers.
For general anonymous communication, The Onion Router (TOR) can be used. For more information, visit the TOR website and the TOR documentation page.
TrackMeNot is a lightweight browser extension written by two NYU students that helps protect web searchers from surveillance and data-profiling by search engines. It does so not by means of concealment or encryption (i.e. covering one's tracks), but instead, paradoxically, by the opposite strategy: noise and obfuscation. With TrackMeNot, actual web searches, lost in a cloud of false leads, are essentially hidden in plain view.
Anonym.OS LiveCD is a bootable live CD based on OpenBSD that provides a hardened operating environment whereby all ingress traffic is denied and all egress traffic is automatically and transparently encrypted and/or anonymised.