Is it possible to run more than 2 DC motors on the Motor Shield R3?

Hello all. I was doing some experimenting in my little lab and noticed that there were quite a few digital pins exposed on the Arduino 2560 mega board with the Motor Shield R3 piggybacked on it. Can I power any of those digital pins to jog another DC motor? I tried but so far no luck. Also, I tried pin 7 and pin 10 on the Motor shield board itself to no avail. Or would it be possible to use an analog pin with another DC motor? I know the Motor shield can supply way more amperage safely to 4 of these little toy motors. Do I need to cut the connection under the Motor shield board to disable braking and sensing to run more motors bi-directionally? Please, any suggestions or comments would be greatfully appreciated. Having a blast tinkering with this stuff.