Think about all the different relationships in your life — parents, children, siblings, extended family, close friends, casual friends, acquaintances, closely collaborative colleagues, professional contacts, superiors, subordinates — our lives are an intricate web of relationships. Yet on the Web — with its capacity for near infinite complexity — these relationships have been reduced to a uni-dimensional descriptor: FRIEND.

Is this really the best we can do? Brad Fitzpatrick, founder of LiveJournal, has targeted social network interoperability as the BIG problem to solve for social connectedness on the Web — and indeed, the siloed nature of social networks could not be more un-Web-like.

But I think the bigger problem is the inability of the “social graph” on the web to capture the infinite variability of human relationships — and the limited nature of social applications, which don’t enable us to communicate and interact with each of the people we know in all the myriad and infinitely varied ways we do offline.

The reality is the the humble text email is still a far more powerful tool for tailoring each of my virtual social interactions to the exact nature of the relationship. On Facebook, Twitter, and even this blog, there’s only one, maybe two “settings” for my social connections.

Social networks are still in the dial-up connection phase — back in the 90s, we marveled at the connectedness of the Web, despite our utterly primitive connection to the network. Today, we marvel at the connectedness of online social networks, even though the connections are still primitive.

So what does the “broadband” phase of social networking look like (to continue the metaphor — yeah, I could just call it social networking 2.0, but whatever)?

Well, how about I share a piece of content and the network “knows” who to share it with. I send a message and the network knows who should receive it. I start a collaborative project and the network invites the right collaborators. I add a new person to my network, and the network introduces that person to other people in my network who that person isn’t connected to but should be. I post an update, and the network figures out who cares to know about it.

Everyone you know is “friend” on Facebook, but why would you ever want to communicate withe everyone you know all at once? Is there ANYTHING that you do equally with EVERYONE you know? Human relationships don’t operate on a single, always on setting.

Some of the metadata we need for the next evolution of online social networking is already part of the social graph — for college students, this captures may different types of relationships:

Facebook Stupid Network

But that metadata is just static reference information — the network doesn’t really let you DO anything with it.

If you want to create a one-size-fits all social network (which is about as useful as a one-size-fits all anything), the least you can do is let me define how I know someone using user-defined tags instead of site administrator defined check boxes.

You know, that Web 2.0 thing.