I guess, you could also argue that in the east coast, people are less friendly, so you have fewer friends and people have to keep them closer and dearly, or that in SF there is a lot of stuff to do, and people can get easily ditracted.
BTW. I am european, so don't want to transform this in a west coast vs. east coast thing.
When it comes to twitter, I am not sure how much the general crowd would be interested in it. Taking example something like blogs: it has instant appeal in a lot of people, because basically it is an online diary.
A lot of people have diaries, and bringing them online was something natural.
But twitter? I am not sure it solves a need to the general masses, except for the hyperconnected ones.
If you think back 8 or 10 years, a lot of people didn't understand blogs. They were dismissed as being the online diaries of a bunch of self-centered 20-somethings and teenagers. Who would want to read that What were they good for?
I think Twitter (microblogging) is in the same place blogs were, and where the web itself was in 1994 and 1995. We're still determining what can be used for and how it can be used. Already, the Twitter community has changed the rules. Twitter isn't what Obvious originally thought it would be two years ago. Keep in mind, Twitter began in March 2006.
So, with twitter, you just broadcast something to a bunch of your "friends", while in the east coast you would just normally text few of your friends directly.
And, there is a good reason they call it "California RSVP". Some people call it shallow, some call it "laid-back", it depends on your point of view, but I have gotten used to it.