Pokémon Crystal Cheats

No Battling Wild Pokemon (Without Repels)
Once you've obtained the HM Cut (HM 1) you can use it to teach some of your pokemon the attack of the same name.
This ability now cannot only be used to cut down certain trees but also to get rid of any grass (by 2x2 squares) so you don't have to bother with any random encounters.
When saving and loading or leaving and reentering the area you used cut in, the grass will have returned (Unfortnately)...