Super Paper Mario Glitches

Under the Shop
Go to the shop in Yold Town. With Mario, flip and then go in front of that sign next to the counter. Flip back, and Mario will be partially inside of the sign. Flip again and Mario will fall down and land somewhere under the shop. To make it more glitchy, walk around. A few seconds later, Mario will be brought back with less health as if he fell down a bottomless pit.