I mentioned this to my re-seller and he thought it was worthwhile to share with the community.
When using Teamwork you can sign in with the marquee but instead of selecting an area of the project, draw a marquee in empty space. You will be able to draw and add items outside of your marqueed area, but you will not be able to modify anything previously placed in the model. Gives the teamleader another level of control. You could even have preplaced sign-in areas off to the side of the model ready for the person to space-bar click on their sign-in space.
