Meet the IW2 from IPEVO: a wireless interactive whiteboard system that turns your existing whiteboard into an interactive whiteboard for richer presentations. It consists of a Sensor Cam, an Interactive Pen, and a wireless receiver. IW2 works with all types of projectors. It is easy to set up and calibrate. You can control your computer remotely, annotate your text/images, and do a whole lot more.
IW2 lets you turn any flat surface into an interactive whiteboard. It is wireless and does not require WiFi to work. It is available or under $170 at this time.