Dec. 14, 2010 at 8:26 AM ET
Ann's tweet above to ask the U.S. Air Force to let Doctors Without Borders' planes to land in Haiti following the devastating earthquake was named one of the most powerful of 2010.
"What really made a difference was that people retweeted it," she said, referring to the act where people send her message out to their followers. "They really made sure that the U.S. Air Force heard it, and they in fact let planes land."
To read about the other influential tweets, click here.
And watch the video below where Twitter founder Biz Stone announces the honor.