The "Rally to Restore Sanity" and "Keep Fear Alive" will be on Oct 30th from 12pm-3pm on the National Mall in Washington, D.C. Jon Stewart and Stephen Colbert will led "a rally for the people who've been too busy to go to rallies."
On the September 10, 2010, episode of The Daily Show, Jon Stewart stating that "I, Jon Stewart, am announcing that I will have an announcement sometime in the near to not-so-near future." Then on the September 16, 2010 episode of The Daily Show, Jon Stewart formally announced the "Rally to Restore Sanity."
The Daily Show and The Colbert Report announced on the October 14 episodes of The Daily Show and The Colbert Report that the "Rally To Restore Sanity" and the "March To Keep Fear Alive" have been consolidated into simply the "Rally To Restore Sanity and/or Fear". Oprah Winfrey also appeared on The Daily Show to offer tickets to the rally for everyone in the studio audience that day.
A "Rally to Restore Sanity" page has been created on Foursquare and according to the information "Check in during the Rally to receive an exclusive Foursquare badge." The page is at: http://foursquare.com/thedailyshow