Google Labs has a new service called “In Quotes” which might be usable to do a truth market of sorts. Here’s the suggestion I just emailed them on this topic:
I would love to use Google “In Quotes” to crowdsource measures of truth.
For instance, I just saw this:
“In a world of hostile and unstable suppliers of oil, this nation will achieve strategic independence by 2025,” said Mr. McCain during a campaign speech. [ Wed, 29 Oct 2008 Washington Times ]
I would like to be able to indicate on a scale from 0 (false) to 10 (true) whether I believed what McCain said is true (that we will achieve strategic independence by 2025). Everyone’s rating would yield an average number (let’s say it was 6.8). In addition, all other quotes that were attributed to McCain would have a truth index too, and the average of those numbers would be his dynamically updated “truthiness” rating. You could add a decay factor to allow for people’s reputations to change over time.
You could then sort quotes and people by their truthiness rating right along side date and relevance when people do searches on news items.
Additionally, you could get a truthiness rating for the sources by averaging the truth index of each quote they publish. Some media like to quote trolls so as to trump up gratuitous controversy, and this would separate those sources from the true investigative journalists.