The advent of large scale online social services coupled with the dissemination of affordable GPS enabled smartphones resulted in the accumulation of massive amounts of data documenting our individual and social behavior. Using large data sets from source such as Twitter, Wikipedia, and others we will present several recent results on how languages are used across both time and space. In particular, we will analyze the role of multilinguals in Social Networks and how language dialects can be defined empirically based on the way a language is used in the real world.