- If you're not familiar with Facebook, Twitter is known as a micro-blog. It's a Web page where you can post updates about events and details about your life that are happening _now_. It has the opportunity to be really stupid, but kinda fun too. You can repost people's items and share information with your friends.
Twitter's question prompt where you type your post asks, "What are you doing?" This has been labeled as "lifecasting" and has the tendency to get boring to your followers rather quickly. (Who really cares that you're getting in the shower, a minute later soaping up your hair, and then three minutes later drying off?) Where I see Twitter's real power is in "mindcasting," or posting short but poignant observations and ideas. Rather, the prompt should be, "What are you thinking?"
This post by Jay Rosen really identifies, IMHO, how truly paradigm-changing Twitter can be. I follow the people I do because I appreciate their great insights, observations, and thoughts about life, media, technology, or whatever. I'm actually kind of glad that not very many of my personal friends use Twitter, because then I'd feel obligated to follow them and then would be subject to having to read about every moment of their pitiful lives.

h34r:
I don't tweet at all about trains (mainly because I don't really have much opportunity to ride them, but also because I'm somewhat of a closeted train addict who hasn't come out yet...). I tend to tweet fairly rarely because I tend to not really have terribly insightful thoughts or keen powers of observations about life and human nature and I don't want to subject my [few] followers (most of whom, though, I have no clue who they are) to the lackluster details about my mundane life. I do tend to post more in the rare case I'm doing something mildly interesting (like my recent experience doing jury duty), but I do try to keep it limited so as to not incur the wrath of those absolutely uninterested in such silly things.
I'll refrain from subjecting you all to the boring details of my personal life and spare you from the giving out of my Twitter name.
