Hi Grant,

Thank you for your question. You can do that using the DataEngine API (there are no specific objects for users or roles). Here's an example of creating a new user:

using Kentico.CMS.DataEngine;
...
GeneralConnection cn = new GeneralConnection();
DataClass userObj = new DataClass( "CMS.User", cn );;
userObj.SetValue( "UserName", "JohnS");
userObj.SetValue( "FullName", "John Smith );
userObj.SetValue( "UserPassword", "password" );
userObj.Insert();

There will be a full-featured API for all objects in Kentico CMS 2.0 (September 2006).

Best Regards,