Looking for research assistance: articles on using NING in education

Hi everyone,
I am in the progress to write a lit review on web 2.0 tools in physical education. I have designed a practicum course using NING and wikis and as it is coming to an end, I am creating a survey. This first pilot study will discuss the use of social networks with teacher candidates in their practicum experience.
I am looking specifically for:
1) Articles for the lit review focused on using social networks in Education.
2) Examples of surveys done using social networks in Education.
I am developing a poster for an International Conference in April and I want to make sure I note the current research.
Thank you so much!
Helena