Lars Wirzenius seems to be seconding my idea for using wikis to solve contentious issues.
My latest idea in this regard is to have several wiki pages, one for each opposing view and one for agreed facts. If an issue has multiple parties debating it then there could be multiple pages for the areas on which different sub-groups agree.
The plan is that each faction edits their own page along with email discussion with other factions and then the page of agreed facts is updated when agreement is reached on some points.
Wikipedia is the canonical use of Wikis for contentious issues at the moment. It is based on having a page for each topic and a discussion page for that page where the history is discussed. This works for Wikipedia because the aim is merely to generate web pages. If the generation of web pages is incidental to the purpose of resolving a dispute then it is a little more tricky. Entire areas of disputed content can be left out of Wikipedia pages without any real loss. But often in online debates the key points are the ones most hotly disputed.
I plan to set up a wiki and do some experiments to see how well this works.