I have just discovered VoiceThread, a free online cool tool to use for discussions about images and video. This is my new favorite, and I've started discussions on my concept map and my knowledge map used in my mind map sabbatical project: http://voicethread.com/share/1199512/.
The maps are not new, but I still hope you check them out if you haven't been to my mind mapping LibGuide (http://bucks.libguides.com/mindmaps). I'm curious how effective you think VoiceThread is for discussing images like mind maps and such. I think it is very effective. The first time I saw this tool, it was being used to discuss fine art. That worked very well, too.
Please leave comments on the VoiceThread site or here if you prefer.