You might have to use a screencast type of program to catch audio and video like Jing or CamStudio. A friend of mine that has a Mac uses Call Recorder and Conference Recorder for Macs (http://www.ecamm.com - inexpensive program with free upgrades). You can also try the 'extras' manager in the Skype tools for the call recorders there as well.
Conference Recorder is another solution: easy way to record your iChat audio and video chats. Conference Recorder is an add-on for iChat which automatically transforms your conference sessions into QuickTime movies. Conference Recorder isn't being updated to Snow Leopard but there was an update last week. You might want to try that application too.