There is a survey about use of social media, from the International Federation of Library associations and Institutions.
"In an effort to learn more about how librarians, library workers, library students, and library associations use social media, the Free Access to Information and Freedom of Expression committee of the International Federation of Library Associations and Institutions (IFLA) has developed a short survey on these topics. Our hope is that the results will allow us to communicate better with those in the worldwide library community - using the most effective tools at our disposal. We're also very interested in those who DON'T use certain social media, and why they don't."
"If you have not yet done so, please take a few moments to complete the survey (deadline: Wednesday, 1 June 2011) and share it widely with your colleagues and members!" Also you can "Be a fan of FAIFE on Facebook: http://www.facebook.com/faife"
In English: http://www.surveymonkey.com/IFLAsocialmedia
En Español: http://www.surveymonkey.com/IFLAredessocial-espanol
En Françes: http://www.surveymonkey.com/IFLAreseauxsociaux-frances