If you don't understand what the big deal is with Twitter, you're not alone.
Dick Costolo, creator of FeedBurner (which was purchased by Google for $100 million), didn't "get" Twitter for a while:
I remember the first time I saw Twitter and thought “I don’t get it”, and then somebody explained it to me and I thought “uh-huh. I don’t get it”, and then somebody explained it to me again, and I thought “Ah!... I don’t get it.” Only after I saw somebody using it in a way that I found valuable did I finally get it.
Me too. I'd heard of it for months before I got into it.
What doesn't help is the appearance of its front page. Until you have an account, it is a barrage of everyone's public updates. It was like being a psychic on a crowded subway car.
Even after that initial barrage, it seemed like blogging for people with ADD. Or a series of iChat status messages. Or a publicly-visible train of thought. Or time-delayed IM. (And it sort of is all of those.)
Yet here I am, four months and almost 2,000 updates later.
What was the segue for me? The social aspect. I found friends who used it and started following them. I'm only slightly more interested in what they had for lunch than in total strangers' noshing, but it was a start.
Before long I saw some more interesting things go by. I learned that there is midnight yoga on Capitol Hill and that the Department of Justice makes their employees use a crippled version of Internet Explorer. I saw some cool links. I saw one guy's father passed away and that a friend was interviewed by Fast Company magazine. I started using it as a non-disruptive way to communicate with my girlfriend throughout the day.
So, just have patience. Add a few people you know. Listen to them for a few days. And you'll "get" Twitter soon enough.