A couple glitches I've found (that may have already been found) are:
There is a multitude of water glitches that allow you to walk on water for a short time (like first logging in or exiting houses) and there is one that allows you to shoot on water by skipping on pumpkin bombs. People abuse this commonly at the holiday shop.
Another glitch is the car inside the 100 your park. When you drive a certain way next to the gate, your car will get inside the starter gate.
Lastly is the trampoline glitch, which probably can't be fixed, but ill say anyways: When there is a trampoline in your house and you delete it while bouncing on it, you will remain in the air.
Graal959714