During level 3, take the second Taxi Bug out to the farthest point that ends in the water. On the right is a rock. Push the Taxi Bug so that it can go through the weed, then position it so it is slanted in the weed and facing somewhat off the rock. Get off the Taxi Bug and walk on the long narrow rock. Then, follow it until you can jump into a white world. There is nothing there but whiteness. You can roll on forever.