Ann Marie Cunningham, center, along with other NASA Twitter followers wave to the Astro van as it passes by en route to launch pad 39A with the crew of STS-129, Monday, Nov. 16, 2009 at Kennedy Space Center in Cape Canaveral, Fla. The Twitter users were part of a unique two-day NASA Tweetup at Kennedy Space Center. Photo Credit: (NASA/Carla Cioffi)

Twitter user Ann Marie Cunningham who goes by the twitter name @talkingscience.org, right, uses her laptop, while Laura Burns, who goes by the twitter name @moonrangerlaura, listens to a guest speaker during a two-day NASA Tweetup event held at NASA's Kennedy Space Center in Cape Canaveral, Fla, Sunday, Nov. 15, 2009. NASA Twitter followers in attendance will have the opportunity to take a tour of NASA's Kennedy Space Center, view the space shuttle launch and speak with shuttle technicians, engineers, astronauts and managers. Photo Credit: (NASA/Carla Cioffi) 

Twitter user Laura Burns, left, who goes by the twitter name @moonrangerlaura, listens to a guest speaker, while Ann Marie Cunningham who goes by the twitter name @talkingscience.org, uses her laptop during a two-day NASA Tweetup event held at NASA's Kennedy Space Center in Cape Canaveral, Fla, Sunday, Nov. 15, 2009. NASA Twitter followers in attendance will have the opportunity to take a tour of NASA's Kennedy Space Center, view the space shuttle launch and speak with shuttle technicians, engineers, astronauts and managers. Photo Credit: (NASA/Carla Cioffi)