If you have multiple organizations and you found a need to get a count of the number of users across all of your organizations, then this utility is for you.
The user interface is pretty simple:
Just enter the credentials of a system administrator-type user who has access to all of the organizations and it will collect information about any user who is:
2) Has a full read/write license
Note: Even though it uses the CRM 4.0 connection to CRM, it still seems to work correctly on CRM 2011.
You may download it here.