Secure Instant Messaging Systems?

Elik writes: "I been asked by the higher up at Netwolves as to the availability of a secure messaging system that uses an encrypted protocol for messaging instead of insecure systems like AIM, MSN, Yahoo or ICQ. From what I have read, they are not secure enough that you can send any secret confidential information though the messenger system, since from the reading, they are not encrypted. Are there secure messaging client/server systems that are available for most platforms, that could be considered secure by using some of the standard encryption systems like 3DES, Blowfish or others?" It shouldn't be too hard to hack support for this into the existing IRC clients. It may not be as cute as most IM systems, but if it's security you want, you may have to sacrifice something. If you are transferring huge amounts of data, why worry about instant messaging systems? Just use PGP (or GPG) to encrypt the data and the plethora of file sharing software currently available on the Internet to get it where you want?