An Activ Slate by Promethean is an excellent way of making an IWB more interactive. The board can be controlled from anywhere in the classroom. It works via a radio transmitter attached to the classroom computer.
The use of a slate also means that the teacher is no lnger tied to the board. He / she can move round the classroom working with children and still be able to interact with the board. The children can also interact with the board from their own desk - thus saving time and distraction of a child moving across the room in order to be next to the IWB.
The slates are A4 sized and use the same pen as the IWB.