Are Social Networks devaluing social experiences?

As I was coming home today I saw a Nokia ad on a bus touting their phones' abilities for mobile, social networking. Apparently Carrie is on her way to a picnic and wants everyone to know how much fun she's going to have. So, Tom something-or-other wants her to keep a sandwich. "All that's left are crumbs" she giggles back, etc. You get the idea.

Anyway, it just struck me that with people broadcasting their social experiences to all and sundry, are they devaluing the more intimate personal experience that's been presented for public consumption? By diluting it with repetition in a letter medium, have they denied themselves the ability to now reflect on the actual experience and from this point on will their memories consist of only the most glaring details of the event with subtleties pushed out by the reprocessing of what is deemed to have "social networking" value? After all, if I go to a picnic and there are people involved that I don't really know or have a passing acquaintance with, it's an ideal opportunity to do some actual social networking and see what they're like as a person. If you're telling everyone what you're up to and they comment or reply back, without participating, what does it mean for you and them that you're now discussing an event which you've shared only in the most tenuous sense but are discussing as if you were all there?

I suppose it just seems strange to me because I'm at that age where I'm technically competent and understand technology but my socially formative experiences were generally face-to-face. I was in my early twenties when I started using BBSes and email over dial-up (and I don't meant the Internet) and from what I saw it only convinced me that only personal interaction will show what people are really like. Too much can be lost or manufactured in the transition from person to screen and back to person again, unless you're prepared to be very specific and unambiguous. When you're on the outside of a flame war looking in, it's very easy to see how foolish the argument is and the end result of things like that is that nothing is achieved, nothing is resolved and very few people learn from it.

It seems to me that social networking sites can be good for reinforcing existing friendships or creating new ones where a real-life connection existed (even if unknown before then) but these artificial friendships lull people into a false sense of social inclusion, until they experience a point where they find out the hard way who their real friends are. Quite possibly I just don't "get" the whole social networking phenomenon, but I just don't see that it is moving us in a good direction.