It occurred to me that if/once we get a working prediction market layer on top of Bitcoin, it could be used for fact checking of online news, blogs, tweets, etc. My thought is that it could start as a web browser plug-in and eventually be built into web browsers, if successful. Anyone could highlight a string of text, right click and select an option to make a bet as to whether the statement is true or false. This would create an instance in the prediction market. Anyone who subsequently sees this web page would see either a green check mark or a red "x" by the statement, indicating whether the prediction market believes the statement is true or false. Readers could then click the check or the "x" to contribute to the bet themselves. All bets would be resolved after a period of time (maybe a week) via whatever system prediction markets ultimately use to verify and close bets. The effect would be a simple fact checking system that could augment any and all sources of text data online without permission.
I'm sure the system would be gamed to some extent and I'm certainly not suggesting this as a substitute for real research/investigation on the part of the reader. It would be important to convey that the results are not absolute; just a "better than nothing" fact-checking system that addresses the accuracy of information at a glance.