It's free and you don't have to "tweet" to have a free account. Most celebrities, non-profits, news orgs, gov orgs, etc. have Twitter accounts and they send out useful info via Twitter.
When Twitter first came out it was meant for this...
"I'm at Arby's eating," or "I've got a headache," "I'm about 30 miles from home." Basically the same thing as Facebook Status.
But now Twitter is mostly used to share news of one kind or another and to share photos, videos, and blog posts. I realize that some of you may not be interested, but some of you would really like Twitter! Blogspot and Youtube work with Twitter very nicely too.