I looked and I don't even have an IRC client anymore. IRCle prefs are still there.
I have been using IVisit. During the printmaking conference we hosted here in Austin I worked on setting up a video connection with a school of art in Athens Greece. In the early testing from home with my humble 26400 connection I was able to send and recieve audio, video and text chat.
You don't need to have a video cam to take part, chat works just fine for convo. I'm using my ancient, fuzzy b&w quickcam.
We settled on iVisit because there are both Mac and PC versions (sorry no Linux, Unix or my beloved ol' Amiga.