Found this graphic in the National Post depicting the number of gun deaths in the 31 days following the massacre in Newtown, Connecticut. The data, as of January 15, 2013 totals 919 gun deaths since that horrific shooting at Sandy Hook Elementary School that included 20 children and eight adults, including the perpetrator. This data comes from the Slate news website (which lists 923 gun-related deaths, and allows the reader to click on each fatality, many of whom are young adults) and the twitter feed @GunDeaths. The data is considered to be incomplete.
Also, I came across this new poll showing that Americans are more angry about the Connecticut shootings than they are about 9/11. If only that was reason for hope for substantive change in America.