How do you Tweet?

I just posted a new tweet on my Twitter account. It said something along the lines of "What's the point of this?" Twitter is the newest fad in social networking. From what I understand (and that's very little at this point), you have a limited amount of space to let everyone know how you feel and what you're doing. It's like a brief play by play of your day. (Because, you know, everyone is just dying to know what you had for lunch, how it tasted, and when you plan on eating again.) A friend of mine has tried explaining it to me, saying that it's a great way to get a sense of the "overall feeling of the nation" based on what their tweets say. So, posting that I just ate a turkey sandwich contributes to the nation's overall dismal feeling on the economy....how? I'm sure Twitter has some great advantages. But my feeling is, it's just another step towards completely alienating ourselves from other people. Instead of picking up the phone and calling a friend, we now update them on our lives through 2 or 3 sentences on our Twitter account? As my last tweet says, I don't get it. Can anyone help me out?