Harry Potter 2: The Chamber of Secrets Cheats

Unic card
Go to the library right to madam Pince and press A on the bookcase and you will find a unic card.

Extra sickle
In the dormitory go a little to the left and at the wood wall look for a real dark wooden block and press the action button and there it is.

Basilisk Hint
First go into battle with the Basilisk use spells in this order: Vermildilius Trio, Skurg Trio, and (CC) Blast Curse and Beat it. Then start a new game on that file and you well be invincible.

Various Cards
All 5 Quidditch players = play games from start screen (Quidditch or practice games)

All 5 potions cards = get 5 invincibility potions (each lasts 30 seconds or so.)

All 5 animal related cards = unlocks a Bestiary.

all 5 famous wizard cards = spell to unlock everything (chests and the golden doors)

General tips
You cant get all 100 Red Tomato beans, or all of the last set of cards without linking to the Gamecube (i have completed EVERYTHING and it hasn't shown up..)

complete all the other bean challenges as soon as you can, and look out for the map, it makes finding secret area's RIDICULOUSLY easy to do. although the 3 bonus area's in the portrait room aren't listed..

look Everywhere!!
complete everything except going to Myrtle at the end, and hunt for everything, and save before the battle with Voldamort and keep your immunity potions, they are a god send!