What is Social in Local, Mobile, Social?

I am working to define a CityGrid Local, Mobile, Social stack, to help CityGrid developers more efficiently build web and mobile apps. This definition will contain APIs, tools, platforms and other data sets that can be used along with CityGrid PlacesOffersReviews and Advertising.

I’m working my way through a bunch of tools and APIs for the local and mobile portion of the stack, but I find myself spinning when I’m trying to define the “social”. Obviously providing information on using the primary social networks in your apps is important:

But where do we go next with social in our local mobile applications? We can find our friends, we can check-in and socially share what we are doing in our every day, local lives--but it seems like there is more that I'm missing.

I have some rough ideas of what could be next for social, but I’d like to solicit thoughts from you developers regarding what is next, when it comes to making your local, mobile apps social. What are you doing in your apps? What do you see others doing?  Ping me @citygridapiteam with your ideas.