When you start your social media engagement you probably start on LinkedIn or Facebook. You explore Twitter and maybe have already an account on YoutTube or Flickr. As you get connected with people you hear about Foursquare, Yelp and Google+, maybe SlideShare and Quora. Others introduce you to LinkedIn Groups or Facebook groups, maybe Focus and Plancast, Tumblr and WordPress. Over time you play with social bookmark tools such as Digg, Delicious or StumbleUpon. Then you get introduced to Klout, Posterous, PeerIndex and approximately 100 or more other tools.
Before you even started to make notes about all your profiles and accounts you have a bigger presence than you think. And now it's getting messy.