Twitter's Lists feature allows you to make a themed list of Twitter users. So, let's say you wanted to create a list of only Teoh Beng Hock or Projectalpha. As you added, you'll be able to view only the tweets from those you added to the list. It's a nice way to edit out the noise. It helps you see only what you want to see. Actually it something like creating a group for your Twitter account. Let's say you interested in Football, then you can create a new list like this "@shun2u/Football", then invite your followers or your friends to join your "Football Club".