How many social networks are too many?

In some ways, we're all multiple personalities based on context.

I am a different person in the context of my family (where, silly me, I imagine myself to be king), in the context of my wife's friends (who think I'm with the CIA because of my mysterious trips out of the country), and in my various professional roles.

So I can completely justify being in multiple social networks with multiple purposes.

But with the explosion of online social networking, I face a multiple-personality problem. How many social networks are too many?

I have 153 friends on Facebook, almost all part of my meandering network of new-media acquaintances. I have 191 professional connections on LinkedIn. I'm involved in several Morris community-networking sites, including a parenting network just launched in Augusta.

And then there's Ning, where Ryan Sholin just launched Wired Journalists, where Robb Montgomery is relaunching Visual Editors, and where I already am a member of the Free Daily Newspaper Association of North America.

Oh, yes: Twitter. I'm not a good twitter-er, so I wired up my blog to post its titles to Twitter, where you can follow me.

If you're my friend on Facebook, do I need to "friend" you on Ning? Do I need to sync my LinkedIn connections? Can't we all just be friends?

[Note: Edited to fix "Visual Editors" and url.]