I'm afraid our project did not turn out as long as I'd thought it would. My niece and I made a marble chute out of paper towel tubes, and attached it to the fridge with magnets. The cool part is you can adjust it up and down and change the angles. The not so cool part is that an actual marble is too heavy for this set up. As soon as the marble hit the second chute the magnets gave way and the whole thing came crashing down. We ended up using a little ball of dried clay instead.
Again, I think I can be accused of picking a project that is more appropriate for a 10 year old than a 3 year old, but E certainly did love the end product! Her face lit up when the ball landed in the Pringles can with a "Clang!" I'm excited to add more chutes...maybe we can run the entire length of the fridge! (By the way, notice the little girlie magnet from Unplugged "Old" looking on!)