RTalk is an easy-to-use chat site built around one feature: anonymity. No signing up, no parting with your email address, no registration. Just start a new session, share the URL with your friends and begin chatting. The URL is encrypted, so only people you want to join in the chat will be there.
If you don't use a desktop chat client, the chances are that you use GChat or Facebook's messages to chat with friends, both of which are probably unsafe. Facebook, for example, mines your chat in real-time for references to other people on Facebook and updates its 'Like this page' feed accordingly (this happened to me and a friend). RTalk is a chat site that promises complete anonymity, as an alternative to established messenger clients.
Create a new chat session by visiting the homepage and clicking on the button. An enrypted URL will be generated for you. Share the URL with your friends. You can now send messages to each other in real-time at the URL. When all of you have left the conversation, your chat logs will be permanently destroyed, unless you ask for them to exported as, say, a text file.