To the best of my knowledge, there aren't any programs that would work with Mac OSX. In theory, iChat could do it (you can do video between two macs between google accounts), but it does not support the right set of protocols/codecs (speex for sound and H263 for video).

On the same google account, I can do video between 2 Nokias or videos between 2 macs, using the built-in nokia client, or iChat. Between Nokia and osx, I can only do text chat. Bummer.