The Access Control Service saw some significant changes with the November CTP release. Prior to that release, the portal was a convenient tool for managing ACS resources graphically. The linked tool is preview of our plans for a UI tool for managing ACS resources and may be a convenient alternative to acm.exe. Please feel free to use it and provide feedback. Your comments are valuable in assisting to create the best possible user experience.You can find the tool at: http://code.msdn.microsoft.com/acmbrowser.This source code is provided AS IS with no warranties and confers no rights.
Update: The AcmBrowser is now included as a part of the Windows Azure platform AppFabric SDK. Please visit https://netservices.azure.com/helpandresources.aspx for more details.