Tor: a free software and an open network that helps you defend against a form of network surveillance that threatens personal freedom and privacy, confidential business activities and relationships, and state security known as traffic analysis
OpenVPN: create an Internet encrypted tunnel between your computer and a VPN server. Data sent by VPN users will be illegible to any third party in the event of malicious interception such as espionage or intrusion.
Tunnelblick: a free, open source graphic user interface for OpenVPN on Mac OS X
Drop Internet explorer or safari, use an open source browser: Firefox with some usefull addons:
Mailvelope: a browser extension that enables the exchange of encrypted emails following the OpenPGP encryption standard
Cryptocat: Cryptocat is a fun, accessible app for having encrypted chat with your friends, right in your browser and mobile phone. Everything is encrypted before it leaves your computer. Even the Cryptocat network itself can't read your messages
Pidgin: A free chat client used by millions. Connect easily to MSN, Google Talk, Yahoo, AIM and other chat networks all at once.