I've found a great new online graphing calculator. Its a lot easier to use than an earlier version I had posted so I have updated the side link as well. You can do all the things we do in class by yourself at home by playing with it for a few minutes. It allows you to graph more than one line and then using the menu above the graph you can create a table and find intersection points. Use the online keyboard to type in your equations.
Click here and then pick "graphing calculator".