I understand it to a certain degree
I agree with the general concept, but the privacy (lack thereof) issue bothers me so. I count on the "don't ask, don't tell" part of life to keep my personal life just that.
I do understand that it is a great way to find old school mates, lovers, friends, blah, blah, blah, but are the details, moment by moment updates, really necessary. Not for me.
One of my concerns about cell phones (and I have one) is that your quiet time is not your own when you have your phone with you, unless you configure it differently (i.e. not to ring). I love it when some goofball is at the grocery store trying to buy food and has to ring home to make sure the brand is correct. Hey, live life with a little danger and buy the brand you THINK you should buy and not call home to get some confirmation on your decision.
I can see that we need one more distraction in life like we need .... well, we just don't need anymore distractions, especially while driving! Now you can be TWEETED while driving! Yes?