While using the LinkedIn professional social networking system recently, a box popped up asking me "Does XXXX Have the skill YYYY?". There were four people from my list of colleagues, each with a skill next to their name, such as "Governance", or "Leadership". I had a choice to confirm they had the skill or dismiss the item. Most of of these I dismissed, but a couple I clicked on, confirming I knew they had the skill.
It was fascinating to see what skills people had against their names. Some did not seem to match what I knew of the person.
LinkedIn goes through what people wrote in their profile and automatically extracts keywords describing skills. You can add or amend these manually. Look for "Skills & Expertise" in your profile.
To confirm others skills, look for a link labeled "Endorse Connections" about half way down the LinkedIn home page on the right. The system displays four people-skills combinations at once. As you endorse or dismiss them it adds more.
There seems to be no systematic ordering to what people or skill is show. It would make more sense if LinkedIn showed you one person at a time and all their skills, or all the people claiming the skills. I have several hundred people in my LinkedIn connections and so I must have clicked on thousands of these people/skill pairs.
This may not seem a very rigorous way to have someone's skills rated, with anyone being able to sign up and endorse anyone for any skill. But if the endorsements are weighted based on the ratings of other people, it would produce a result similar to that used for ranking academic papers, which is in turn used to determine the appointment and promotion of academics.