Delegate Security Role
Microsoft Dynamics CRM 2011 includes the Delegate security role. The only privilege in this role is "Act on Behalf of Another User". This role on its own does not provide access to Microsoft Dynamics CRM and must be used in conjunction with another security role. The privilege "Act on Behalf of Another User" allows code to run as or impersonate another user as described in this link http://msdn.microsoft.com/en-us/library/gg334744.aspx.