Perry uses the Lominger and the Birkman 360 tools. A tool like SurveyMonkey can also be used for quick, anonymous queries.
Wikipedia explains 360-degree feedback as:
In human resources or industrial psychology, 360-degree feedback, also known as multi-rater feedback, multi source feedback, or multi source assessment, is feedback that comes from members of an employee’s immediate work circle. Most often, 360-degree feedback will include direct feedback from an employee’s subordinates, peers, and supervisor(s), as well as a self-evaluation. It can also include, in some cases, feedback from external sources, such as customers and suppliers or other interested stakeholders. It may be contrasted with “upward feedback,” where managers are given feedback only by their direct reports, or a “traditional performance appraisal,” where the employees are most often reviewed only by their managers.
The results from a 360-degree evaluation are often used by the person receiving the feedback to plan and map specific paths in their development. Results are also used by some organizations in making administrative decisions related to pay and promotions. When this is the case, the 360 assessment is for evaluation purposes, and is sometimes called a “360-degree review.” However, there is a great deal of controversy as to whether 360-degree feedback should be used exclusively for development purposes, or should be used for appraisal purposes as well.
 Bracken & Rose, 2011; Maylett 2009
 Waldman et al., 1998