This blog post originally appeared on the web site of the Harvard Business Review.

Of all the problems that plague the plugged-in, social worker, one of the simplest remains the hardest to solve: Syncing contacts. Most of us have so many contacts spread across so many networks we lose track of them, can’t access them when and where we need to and miss opportunities to connect. All we want is to synchronize all of our contact lists. A master rolodex. Why is that so hard?

Google offered to connect me with Joseph Smarr, the former CTO of Plaxo, a company that’s been trying to create this for the past 18 yars now; Smarr is now with Google on a team focused on the social Web. I asked Smarr to help me understand the limitations of contact syncing today, why something so simple is actually complex, and when we can expect it to get easier.

Why can’t I keep my Gmail, Twitter, Facebook, and other contact lists in sync both ways, right now?
Smarr: It’s basically technically impossible. And that’s assuming all the parties are cooperating, which they aren’t, and that it’s what you actually want, which you don’t.

I don’t?
What you actually want is a little more complicated than “make it all the same everywhere.” If I’m connected to somebody on LinkedIn, I want them in my address book, that’s pretty clear. But then if I disconnect them from LinkedIn, do I want their info deleted from my address book? Maybe not. And do I want to be connected to everyone on LinkedIn who is in my address book? Maybe not. Some people use multiple social networks with the same sets of people and want it to all sync. Some people partition different aspects of their life by keeping LinkedIn just for professional stuff, or Facebook just for friendly stuff, or Twitter just for celebrities. Different people end up wanting different things.

The whole Buzz rollout has been the most notorious fail of the year around not being careful about how people want to use their contacts across different contexts. What lessons can you draw from that experience?
You have to make sure users really understand what they are doing and have the right controls and don’t get surprised. The rule is, if you’ve surprised your users, then you haven’t done a good job. The problem is you can’t always anticipate what’s going to surprise users, and different users have different expectations. Lots of Buzz users were very happy: thank goodness that it magically helped me follow all these people and didn’t make me do a whole bunch of work. And other people were surprised and dismayed. It’s exactly the same functionality, so one-size-fits-all doesn’t always work.

How do you manage relationships across different social networks?
I’m a great example of someone who doesn’t have the tools I need to do as good a job as I’d like to do. The challenge for me is that not everyone is on every platform, whether it’s Plaxo or Facebook or Twitter. That’s why I’ve been so passionate about open standards for moving data between these social networks. I shouldn’t have to get everyone on Gmail just so I can email them. I shouldn’t have to get on Sprint to call them. It’s lunacy to think that we have to get everyone in one place because that’s the only way sharing will ever happen.

So how do we get companies to let go a little bit and cooperate to help us manage contacts across networks?
The game-changer is the rise of smartphones. Social media players need to be on smartphones to be relevant, and it’s forcing those companies to build all the APIs they’d need to play with each other as well.

So all I have to do is wait a little longer until this problem is solved?
Consumers need to demand this, use Get Satisfaction, and blog, and ask companies “How come it doesn’t work this way?” Anyplace where you store data and don’t have sufficient access to make it work with the other tools you use, you should be making those companies aware that you’re not happy about it.

But if Facebook and Google aren’t agreeing on a way to help me sync those contacts, how can I know who to lobby?
The problem is that a lot of the sites don’t want to publicly shame the other sites by saying “Click here to connect with Facebook — oh, doesn’t work? Go yell at Zuckerman.” Plus, there are legitimate concerns on behalf of LinkedIn and Facebook and others around protecting their users’ privacy. But ultimately you either trust users and try to give them the tools to help them make smart decisions and to clean up the damage after the fact, or you act paternalistically and say sorry, we need to save you from yourself.

Has managing contacts become a mass consumer problem, and not just a problem for us geeks?
Absolutely! People want to stay in touch with one another. That’s a basic human emotion. And people are using all kinds of different tools because we’re in a world where nobody has dominant market share. Whether it’s sharing status updates or sharing photos or just knowing where your friends are and what they’re doing, that fragmentation is going to continue, and it’s very healthy as long as consumers have the choice to connect up the tools they use and communicate across the services.

I’ve been at this over 8 years and sometimes I’m not sure we’re any further ahead than when I started. But this has become more of a mainstream problem. Before social networking and before smartphones, maybe this was a power user problem. But now everybody is faced with this.

And people are so used to this all being so terrible that a lot of them don’t even realize how good it could be. It’s only when you have a taste of this magic that people will crave the work that it takes to get it done for real.

Meanwhile, it feels like a full-time job to manage all my data.

It is a full time job. And that’s the other sad thing. Think of all the great content and personal interactions you’re missing and I’m missing and that we’re all missing. It’s one of those things you don’t notice because you don’t see it.

But think about the moments when your friend shared some photos or a blog post or something, and you think, I would have missed that you’d done that. And I’m so happy you got married or you went on a cool trip or you got a new job.

And you know there are so many more people you care about who are doing those things. You’re just not hearing about them, or worse, they’re just not sharing it in the first place because they’re so pessimistic that the right people will even hear it, or that they’ll be able to do it with the right level of privacy controls.

There’s so many great human-to-human moments in store of staying in touch, and having a more intimate relationship, and sharing that joy — if we can just work things out. That’s what keeps me motivated.