July 5, 2011 10:16 pm Twitter Knocks on White House Door Matt Browne, digital media expert, explains Pres. Barack Obama’s Tweetup and how people can participate. US & World Videos 2:05 Police find, return dozens of abandoned Amazon packages 0:28 A Vermont state trooper plunges into icy pond to rescue 8-year-old girl 2:59 Keep these travel etiquette tips in mind this holiday season
