Using Social Media in the Classroom

How can teachers use Social Media in the classroom as both,  part of the instructional approach in teaching as well as helping students understand the online web 2.0 environment?

I think teachers should be teaching in a way that is most engaging for students, and today that is by using social media.  I think that if students are going to try to be on social media in your class anyways (a common problem with every student having a cell phone) then why not go with that and use social media for your benefit.  The bonus is that there is usually no need to really explicitly teach students how to navigate social media sites, and often they might teach you a thing or two.  The way to use it appropriately is what will be explicitly taught while using it for instructional purposes.  How to safely use social media is something that will (hopefully) translate to their personal usage as well!