Cellphones - they're simply tools
Some good examples of mobile device use in class. Many of these strategies would also work with iPads, or iPods. A couple of very useful applications are also profiled in this article.
"...In the most ideal class settings, mobile devices disappear into the background, like markers and whiteboards, pencil and paper – not because they're not being used, but because they're simply tools, a means to an end. The "end" can be any number of things: to gauge student understanding of a concept, to capture notes and ideas to be used and studied later, to calculate, to communicate, to express ideas...."