I have mix feelings about using social media in the class. I do not use Facebook or Twitter. I have flirted with the idea but have so many students that refuse to expand their thinking.... tweet on their essays and respond on such a shallow level that I am afraid that using these will only encourage their lack of depth.
I know some teachers that tweet the homework assignments to their students, claiming that the students forget, and are more likely to do the work if they get a reminder. This seems too enabling for my liking. I already post the assignments on the white board and web page calendar along with the announcement in class. I feel they should be able to write down their assignments and focus on how to time manage. However, I do use other versions of social media to engage the students: discussion threads, wiki pages, and ScoopIt.
Discussion Threads creates a virtual learning environment for students to interact that is logged and quantifiable. I use the discussion app built into Schoology a Learning Management System for my classes. The discussion thread in Schoology allows me to give a grade, respond to the students posts, ask additional questions and stimulating higher order thinking. An additional application that I have also used is VoiceThread. This application allows the students to add video and voice to their posts. The threaded discussions require all the students to interact with the content in a more reflective manner than just a few responding to a question in class. They also create a virtual learning community with their peers much like a virtual study table.
I also use PB Works, a free wiki page, allowing student to create wiki projects. I like the way the students have to think how they organize the content by creating links through tags and sub pages. This formate forces the students to synthesize and distill the many resources available to the 21st entry scholar. It also creates a structure for peer edits and review.
Scoopit allows you to curate web pages and digital media. Students can browse content that I have chosen read and post their comments. I use ScoopIt more as a holding area for articles that I find during the year to use for future lessons. I also "follow" other teachers and professionals in the same field. The students can create their own ScoopIt page and curate webpages for projects, share and post on each others pages.
I feel that each of the resources above help students organize, think deeper, and promote a learning community.