While not strictly a Dynamics GP tool, AuditNet.org has a great, free Segregation of Duties Tool. This Excel tool allows a company to enter a person or role and then check off what that person can do. The tool then figures out where the segregation of duties conflicts lie. This is a fantastic starting point for working with GP 10 or 2010 security to help figure out what user roles should be and what access they should have. Having this as a starting point really makes setting up and documenting GP security easier.