Twit?

I recently received some advice from a friendly fellow blogger.  She encouraged me to join Twitter.  Naturally, I'm cautious and hesitant about it.  I was wondering who else out there is tweeting and what your reservations (if any) were initially.  I only glanced over the terms and conditions and the first thing that jumped out for me was the clause that warns that anything you tweet might be open to the whole world.  That's a scarey thought for me.  How did you all overcome this fear?  Is tweeting worth the rage?  Don't leave me hanging here...let me know something.