New Super Mario Bros. Glitch
by jdaster12.8

In the 2-player Mario vs. Luigi mode in New Super Mario Bros., there is a spot where it is possible to go through a floor. Normally the thin, blue, blocky floors can be jumped through with a regular jump, but you have to go around them to go back below them.

In the 2-player castle stage, there is an area that is supposed to be reached only by Mini Mario containing 4 coins. However, with erratic jumping, ducking, and/or Ground-Pounds when the ceiling comes down, it is possible to go through the floor with any power-up, at least one out of every three tries.

This may be possible in locations in the 1-player game too, but so far I have not located similar areas other than a small overhanging ledge in the first tower level.

Paper Mario Rare Item Locations

Ultra Shrooms:

1. In the first screen above the tent in Dry Dry Desert, hit the yellow block once for a Mushroom, 10 times for a Super Shroom, and 100 times for an Ultra Shroom.
2. After giving the bucket and scarf to the snowmen, sleep in the Shiver City Inn for 4 mushrooms and an Ultra Shroom.
3. Tornado Jump under the Brick Block in the first screen past the snowmen twice, once to break it, and once to uncover a block with an Ultra Shroom in it.
4. In the second large, multiple-path area in Bowser's Castle, take the upper-left path for a bonus area containing an Ultra Shroom if you solve the puzzle.
5. Right before the entrance to Peach's castle, there is a Save Block to the left of a bridge. Jump around on the right side of the bridge to uncover one last Ultra Shroom.

Jammin' Jelly:

1. Look behind the big tree to the right of Yoshi Village.
2. As Princess Peach, answer correctly at least six questions on the quiz show during the chapter 5/6 intermission for a Jammin' Jelly.
3. Hit the lone tree past the well with Lily in Flower Fields. (Unlike the other trees in Flower Fields, you can only get one Jammin' Jelly from it.)
4. After the second Guard Door (that asks the memory questions), fall down from the the first flight of stairs to find a Jammin' Jelly on a small ledge.

Repel Gel:

1. One of the blocks in Gusty Gulch contains a Repel Gel.
2. You can buy a Repel Gel from Rip Cheato at the end of the Toad Town Tunnels.
3. A Repel Gel is hidden behind a tree near the upper-right corner of the screen with the snowmen in it in Shiver Snowfield.

In addition to the items mentioned above, you can get Jammin' Jelly and Ultra Shrooms from silver and gold blinking Li'l Oinks, respectively.