Cryptographic IRC?

cylent asks: "I have a close-knit group of acquaintances that like to communicate with each other often. Public IRC servers are fine for chit-chat, although for more in-depth discussions a more secure form of communication is preferred. I'm wondering what GPL'd software exists to provide for a secure form of realtime multi-party communication. Are there any IRC servers/clients that support any form of public key cryptography? Blowfish? 3DES? Are there any other proprietary "chat" programs available with a forte in cryptography?"