With a tool like Dabbleboard, you can send out the URL to a class so that they can interact from their seat, or get up and write on the board. Plus, with a saved link, you always have an easy artifact not attached to Activ or SMART software. Also embeds.
While this tool doesn't give you URL or embeds, it's super easy to use, which can engage younger students very quickly. I always tell people to go the Web first and show off some of these web white board tools to teachers to hook them. Much of the software in Promethean and SMART can be overwhelming to teachers who fear technology. Engage them first with this tool.
Everyone wants to make Jeopardy games or Wheel of Fortune in their IWB software. Well, here's an easy cloud tool that works great when used with a smart board. Of course, use it as a pre-test, a formative assessment, or for just plain fun. But again, with a save-able URL, I feel better organized having my tools on the Web.