A social media network that would be useful to me as a Spanish Teacher would be Yahoo Groups. There is a group called Maestros de Espanol. This group is perfect for collaborating with other Spanish teachers. I could share anything I find interesting with regards to Spahish or pedagogy. I could also share lesson plans and web resources. I could even view other teachers' Pinterest boards and share my own.
Another use for Yahoo groups I would have would be class groups. With our class group, I ould communicate easily with students who have questions about assignments Students could also communicate with each other for practice. I could have them post a current event from a spanish speaking country each month. The possibilities are endless.