Check out this Casio ClassPad 300 Touch-Screen graphing scientific calculator. The 160×120 pixel touch screen lets you enter equations as you would write them and let’s you see a graph, even 3D ones with a rotate and zoom function. It has a drag and drop feature making navigation and usage very easy and also supports learning very well. If I had one of these when I was younger, I would definitely have been the “coolest” (or is it geekiest) kid in school. It is available in Amazon with the price of USd149.99 with free shipping service.