I've recently moved my personal site from Tumblr to Posterous.  It was an easy transition as I didn't bring over legacy content from my Tumblr site -- much of it was just a series of my Twitter posts which were pumped into Tumblr on autopilot.

Going forward, however, I'm thinking about (and asking you about) ways to simplify my online presence.  Is it better to divide your time between 5 different sites so each site only gets about 20% of your attention, or is it better to focus on 1 or 2 sites where you can focus 50% to 100% of your time and resources on contributing to conversations, etc?

Like many people, I'm on Twitter, Facebook, LinkedIn, Friendfeed, Tumblr, Posterous, and other iterations of what are all now collectively refer to as social networks.  I also have a site/blog on Squarespace that I use for my financial planning business.

I'm thinking about focusing on my Posterous and business sites and leaving the rest to happenstance.  Posterous, as well as many other sites, makes it simple to syndicate your content around to other sites easily as you're well aware.  So I can still write on Posterous and have the content flow to Twitter where it can then be picked up by Friendfeed.  And I can monitor specific RSS feeds to see when people mention @russthornton on Twitter or leave a comment on my Friendfeed stream.

Facebook has been a great tool to reconnect with many friends from grade school all the way through college, but I'm losing patience with all the Mafia Wars invitations and other things on Facebook and other platforms that I'm not interested in.

So, I will defer to anyone who cares to comment, because you likely have much more experience in these matters than I do.  Here's the question:

Is it anti-social to be less social on social networks and instead focus on one or two platforms where you can be more committed to participating in conversations and contributing to the community?

I welcome any feedback you're willing to share.