As someone who has been selling and distributing interactive whiteboards and projectors for 9 years, I wouldn't recommend SMART boards under gunpoint. They are delicate and easily damaged, expensive, and in my personal experience extremely frustrating to use. SMART dominate the market because they pre-date most other manufacturers, and insist on finger-touch technology which many (including myself) find frustrating and inprecise to use.
I sell Hitachi Cambridgeboards to trade customers - extremely tough and durable, they use a pen (which is a writing tool - not your bloody finger) they are far faster and responsive than touchboards, and the software is developed by Cambridge University Press.
Promethean aren't bad either - similarly tough and responsive, software isn't as good as the Hitachi though.