Many people comment on the irony of how the modern world makes people feel isolated despite giving them more means of communication than ever before. For example, I don't know anyone that lives in my neighborhood, and I think this is common. Social software doesn't help with this, typing "A/S/L" into an AOL chat room doesn't really enhance my social life, neither does posting a pic on Myspace.
Now think of the appeal of geographically local communication tools. For example, maybe a chat room would be localized so as to only cover a local coffee shop. People in the chat room could leave away messages about what they're reading, and others would comment on it. After a good IM conversation, people might walk a few feet and have a conversation in real life. I might meet someone everytime I go to the coffee shop, whereas now I might meet a new person every few months. "True social" software facilitates socialization in meat space and helps to break down the social barriers that prevent us from knowing our neighbors.
Another example, I would like to have a bulletin board that only covered the community where I live. Then I could post messages about the barbecues we have and I would finally be able to meet people that live around me.
Craigslist is "true social", and so are dating sites today. I would like to see the genre expanded.