Take a Look at Debategraph

http://debategraph.org/ Check out the Climate Change debate featured on the home page.

It's a collaborative, creative commons social venture that combines web-based, argument visualization with collaborative wiki editing to make the best arguments on all sides of complex public debates. Best of all, it's a free tool.

Look at the "about" tab to figure out how it works.
Look in the gallery to see more kinds of maps. There is one started on "Intelligent Design"

Read the BBC article in which founder David Price says that it's better than a blog format on complex issues.

"The way that the map works is that once an argument is being represented on the map, it's there and everyone can see that that argument is being heard.

Then the question becomes, can you improve that argument or can you respond to it and challenge that argument?

This tends to lead to more constructive discussion...". Here's the thing: It allows students to collaborate in the real world. Sounds like something we should explore.