The Presence tool allows you to put a numeric score to how effective you have been in creating your profile, building connections, giving and receiving recommendations and participating in LinkedIn Answers. It also records your score and returns an average score based on people that have previously rated themselves. Now you can see how effective you have been relative to others.
This was originally designed as a paper based scoring tool to be given out as a bonus to anyone buying the Got LinkedIn book. After some thought, I decided that it would be better suited as an electronic tool that would allow you to compare yourself to the average score generated by other users.