Back in 2007 someone used a “#” to make note, and to attempt to group together comments on a specific topic on Twitter. While somewhat annoying, and it consume some of the 140 character limit it stuck and took off. Today, while still annoying, it is the premier way we group thing in Twitter and is attempting to get into Facebook, LinkedIN and other Social News spreaders. It is the way we search for things that we are looking for or current events being blogged or SMS or Tweeted about. The chart is really quite well done, and there are some other thoughts by the author to consider.