Paper Mario Hints

First, get the Super Boots. Then, go to Mario's house via Toad Town and stomp the ground inside Mario and Luigi's bedroom. Eventually, you'll see a tile on the floor going up when you stomp. Stomp on that tile and the floor will bust open Luigi's secret basement, and inside is his own secret diary!

In Boo Mansion, go through the door across the hall from the entance, the one with a large jar in it. Jump in the jar and NES Mario pops out! Leave the room or jump back in to change back.

To give Luigi a real scare, exit Boo's Mansion BEFORE getting Lady Bow. Return to Toad Town (You still have to fight Jr. Troopa, darn it), jump into your Pipe, and return home. Enter Mario's room and look for a strange-looking part of the floorboards (Entrance to Luigi's Diary). Go through and Luigi will be writing in his diary. He sees you, becoming stunned for a moment, then fleeing.
For fun only. Does NOT affect storyline or Luigi's Diary entries.

Go to the Flower Feilds ( Chapter 6 ) and go to the Yellow flower gate. Then, go contiuly down until you cross the path. Then go back and you will see an Amazee Dazee! Then use your SPin Confusion Badge to hit the Amazze Dazee confusing it. then beat it, you will get at least 40 sum Star Points. Then, go back to Toad Town, and pop right back in the Flower Feilds. Then keep reapeating the process until you have maxed out your level.

In Bow's mansion, go into the room with a large pot that you can jump into. You'll come out as a Pixelated-Mario! You can't pause, change partners, use items, use your partner, use your hammer, press C-up, spin dash, or talk. But if you leave the room, you'll turn back to normal.