There was a beta of an Add-On, surveillance. Someone, I think Aloshi, made it, but it forgeted up when you respawned so he tossed it and never fixed it.
It worked by using a camera wand. You hit the brick you want to be a camera and then hit another to be the camera "viewing" brick. When you clicked on the "viewing" brick, it allowed you to see all around it.
EDIT: Oh, and a one-way window brick has been made in part of a windows brick pack.