The Nightmare Stone Cheats

Blow up Lara.
At the title screen, press A, A, B, B, A, B, B, B, A.

Cracking Lara's bones.
At the title screen, press A, A, B, A, A, A, A.

Lara and Winston the butler at Lara's house.
At the title screen, press A, A, B, B, A, B, B, B, A.

Source: neoseeker.com