For the last 10 years, researchers led by William Hirst of the New School and Elizabeth Phelps of New York University have been tracking the steady decay of what people recall about that tragic event.

WSJ: Jonah Lehrer on Memory, Witnesses and Crime | Head Case

In advance of the event, social media management service HootSuite launched a Wrestlemania 29 Command Center, tracking social media conversations, including sentiment, Tweets, Facebook likes and number of mentions around the highly anticipated rematch.

FORBES: WWE Wrestlemania 29 Social Media Command Center Created For Wrestling Fanatics

Built on the NationBuilder platform, a startup that has been catering to smaller organizations looking for less expensive "campaign in a box" tools, NewtHampshire has every bell and whistle you could ask for: user profiles, badges to reward volunteer activity, tracking links so users can monitor their own progress recruiting others, event hosting tools and a public leaderboard to spur activity.

CNN: Is Gingrich's 'NewtHampshire' site too little, too late?