mathisfun.com: Interactive Cartesian Coordinates. This is a great tool to learn about the coordinate grid. It can label the quadrants, plot ordered pairs, draw lines between points, and can be used to show transformations in math--like a reflection over the x axis.
Thinking Maps :: I began using these last year with great results! We loved using them to organize our thinking and they became an important part of our classroom toolkit. I'm looking forward to using them from the start this year.