I am trying to modify the custom activity that I discussed in my last post that checks if a user is a member of a Sharepoint Group, so that instead it checks the AD Group. I am looking for a great resource on directory services and the search feature, so that I can search for the user in the group. I am also curious if I am going to need to implement some type of impersonation, so that the workflow has access to check the AD Group User Makeup. Any information would be appreciated. When I am done I will post the code, so that people can use it in future.