Add field to "Add New User" Screen to pick User Group

Is there a nice way to add a field to the WordPress “Add New User” Page to pick the Role Scoper User Group during a backend registration? This would make my life a lot easier. I know there is a way to add extra fields. I found an article made by Justin Tadlock here. I just need to make the field update the user group and add the user to the group of choice using a drop down.