Win Crypto Chat is a program that allows 2 parties to chat to each other over a direct TCP/IP connection with ridiculously high levels of encryption which is all done in the background automatically - no central server or key management hassle required. download it here (includes Delphi source).

There's a screen shot here showing an imaginary conversation between Avi and Randy.Note - the Java and Windows versions are *not* compatible with each other, i.e. you can't connect to the Java version with the Windows version or vice-versa.