John has been using the Gyration Mouse and Keyboard System and say's that he will not be recommending any more IWB's for the upper school. Though I agree they have a great place in the lower primary classes.
This is my experience as well.
I have been using the Logitech Bluetooth Mouse and Keyboard for quite a while now. and have always liked the freedom. It is the basic way of interacting with a class via a projected image. This took me onto the Interwrite ClassPAD.
This is a great way of getting the an intermediate level of interactivity into the classroom. It has dedicated software and can, again, be used from anywhere in the classroom.
The fully interactive class will be when the pupils have UMPC's, the teachers have tablets both connecting to the network and the projectors wirelessly.
Not far away now .......