When I was a kid, there were no graphing calculators. In fact we couldn't use even simple calculators until my senior year. I think even Calculus can be taught. very effectively without graphing devices.

Popular journalism (Wash. Post) story claiming that cell phone apps are beginning to threaten graphing calculators as the tool of choice in classrooms. Advantages to apps include price, and not needing a second gadget. This is of use to teachers, as not all students can afford a graphing calculator. Not all students have cell phones either, but this provides another option that will work for some students. Also useful on the days Johny forgets to bring his calculator, but has his phone.

Here's a brief article about Cell phones beginning to outpace graphing calculators.