I've used Twitter on very rare occasion. In fact, last fall I tried it a little bit while I was deer hunting. My wife was working much of the week and just wanted me to check in every once in a while. Since she can't use her cell phone in the hospital, but has web access via computers, Twitter let me send quick text messages about where I was and when.
I also used it to provide updates to our families, while our kids were competing in some out-of-town hockey tournaments.
Aside from that, I don't have the time, energy or inclination to share details of what I'm doing. Nor do I care what other people are doing.
BTW, the term "tweets" is damned near a deal-breaker for me. My best friend has been living the full-blown tech life (programmer for a major software company in San Jose since '95 or so) and his opinion of Twitter is that it's just a huge time sink. He's commented that the folks who use it the most are often the least productive, due in large part to the amount of time that they spend sending updates and following the minutiae of others.
