Speaking of HOPE, a new secure AIM client was announced and distributed there.
ScatterChat is a HACKTIVIST WEAPON designed to allow non-technical human rights activists and political dissidents to communicate securely and anonymously while operating in hostile territory. It is also useful in corporate settings, or in other situations where privacy is desired.
If you are interested in a more secure AIM session in Windows or Linux, check Scatterchat out. It uses four different encryption schemes, including the ever popular 256-Bit AES.