I just had this discussion with my wife over the weekend, but in our case we were talking mainly about Facebook and not Twitter, but the same principal applies. My take is that I like the concept of being able to keep in touch with friends and family easily, but the implementation of facebook, myspace, twitter, and sms messaging leaves a lot to be desired. Facebook and myspace allow other people to post things which you may or may not want posted about you, and it keeps those postings for a certain amount of time (# of posts). Yes, you can delete them, but that's not the point. If there was damage, it's already done. Twitter is completely abused by people posting things about going to the store or going to a movie. Who really cares about that except stalkers or people who need to live vicariously through other more exciting people? I see the point for texting/sms, but I can't stand hearing about people that constantly text their friends. If you need to have a conversation with someone with multiple questions and answers, then it's a lot quicker (and cheaper) to call them. It's only quicker to text if it's a single message with a single response. Yes, I'm very technologically literate - I have worked in the computer networking hardware industry for ten years. But the implementation and addictiveness to many people of these four services is really bad. I know a few people who use these services solely for posting pictures and stories for family and good friends - I definitely get that.
For the flip side - my wife uses facebook quite a bit and likes getting updates from people she probably wouldn't call and talk to. Also enjoys looking at pictures when someone posts them. I get that - I just don't get the constant attention it requires. I look at her page, and see 3-4 updates from some of her friends on a daily basis, and we're not talking high school or college kids here. And half of them are lame attempts at introspective comments like - "can't wait to go drinking", "feeling lonely", "two days until the weekend", "my life is like xxx song lyric", etc. She agreed with me about that stuff, but it seems like most of our joint friends enjoy posting comments like that. As for twitter, she equated it to instant messaging. Definitely not the same thing because it's kept forever and isn't a two way conversation.
I'm not starting flames. I just don't understand why so many people are so addicted to these computer based types of social networks when to an outsiders perspective many of the posts seem either phony or useless. There have to be other people out there that agree with me, or that can come up with rational reasons as to why I'm wrong.