The moment of silence was requested by Connecticut Gov. Dannel Malloy, who issued a proclamation calling on the citizens of Connecticut to observe Dec. 21, 2012, as a day of mourning. Malloy sent a letter to all the nation's governors asking them to observe a moment of silence in remembrance of the fallen.
President Obama said he will observe a moment of silence at 9:30 a.m.
Patch sites across the country will mark the tragedy at 9:30 a.m. EST and "blackout" for five minutes.
Among other sites taking part in the Web Moment of Silence are Adobe, Foursquare, Hacker News, Duke University Jawbone, Salesforce and others.
How will you participate? Tell us in comments.