Anti-Social Networking?

No, my post title doesn’t mean being against social networking, though I may indeed be turning against it more and more.
The title refers to the possibility that social networks are actually making us less and less social.  Hence, “Anti-Social Networking”.
Let me go back to what got me to this point.  You see, recently my wife and I had the privilege of going out to a restaurant with some dear friends of ours.  As we were enjoying our meal, I started to notice how many times one of our friends took out her phone to type something on it.  It eventually got to the point where we would be in the middle of a conversation, and she would take her phone and go into an almost comatose state, responding with “hmmm” and “uhu” where appropriate, but with no other form of response.  Not laughing at jokes, not responding to questions… Nothing.  Just staring at her screen and typing.
It turned out that she was chatting to another friend of hers over an instant messaging service that’s very popular in South Africa but won’t be mentioned here.
As I noticed this, I looked around and started noticing other people at other tables with similar problems.  The only difference is that most of them didn’t notice that there was a problem, because at most of those tables, all of the people were doing exactly the same thing.
This reminded me of some wise words I once heard (I can’t remember who said them so I don’t know who to credit): “Wherever you are, BE THERE.”  My friend was with us in a restaurant, but at the same time she was really with another friend of hers somewhere else.  Which begs the question, why not rather go out with THAT friend then?  With this in mind, is it any wonder that some restaurants are starting to offer substantial discounts to people who are willing to leave their mobile phones at reception?
My theory is that social networks (especially those that have, or primarily are, instant messaging services) may actually be making us LESS social.  So what can we do about that?
Well, first of all, I recently switched to another phone.  Still a smartphone, which makes life much easier for me.  But not the smartphone that I used to use.  The old one made addictive instant messaging way to simple.  I’m done with that.  It was a conscious decision that I plan to follow through with.  Secondly, I have decided to always be where I am.  Unless I’m expecting something important, I won’t even answer a call when I’m socializing.  Yes, my phone will be on and I will see who it is, and if it could be important I will ask if I may be excused for one moment.  But if it isn’t important, then I will just let it go to voicemail and phone back later.  It’s just common decency.
I think we can all do well to remember the basic manners that we learned about communication, and apply those same rules to phones and social media.  When you are busy with a conversation, don’t let someone else cut in.  Focus on the person you are with and nobody else.  They deserve your attention since they are taking the time to be with you.
So what are your thoughts?  Am I right, or am I way out of line here?  Speak to me.