I love Twitter!  I actually use it now for research, and love to watch the "backchannel" while live events are happening on TV.  All you have to do is type a hashtag (#) and word in the search box and you'll see the feed in real time.  For example, last night during the American Music Awards, if you followed #AMA, you'd have seen all the reaction to Adam Lambert's number.  Why the book cover?  Because when David Pogue (CBS News, New York Times, etc.) put out daily "prompts" last spring, I replied.  3 of my tweets were chosen for his book, and I got an autographed copy!  Very cool!