Introduction to 360 Degree Feedback
The basic premise of 360 degree feedback is that rather than being given performance feedback at work solely by your superior, the feedback comes from people all around you. This would include your manager and your peers, but could also include your direct reports, and people that you work closely with from other areas of the business. For example a developer might receive feedback from the rest of the development team, the design lead, and the project manager.
A key element of the 360 degree feedback, is that it is often made public (but anonymised) for all employees - from the top dog downwards. This allows everyone to see one another's feedback. It is also common to ask the employee to give feedback on the feedback (confused yet? I once wrote a web system that did this!!), and the aim of this is to encourage the employee to reflect on their own behaviour and achievements, and see how they align with the way that others perceive them.
360 Degree Feedback for Skills Analysis
The reason I brought up 360 degree feedback in my talk "Teach a Man to Fish" (slides are here), is because the talk is about team coaching, and I advocate the measuring of skills before and after you strive to improve them. One very effective way of fairly measuring skill levels on a number of different areas across a team is to ask everyone to rate one another on the areas given. This works especially well with developers because they have a much better understanding of one another's strengths (and weaknesses) than management do.
Have you used this technique? Which bits did you use and which did you change? I'm starting to use it with the teams I coach and am always interested to hear of others' experiences.