For those of you that like things like action replay, Gameshark or any of that garbage, you would definitely like changing games like Pokemon or Sonic ect. to the fullest extent.

Link to the ROM above. (REMEMBER, it is unfinished so it wont be all that good.)
http://www.filesavr.com/rom
You can do anything with the games you changed. Like on this game, Pokemon LeafGreen, (Pokemon is the most hackable game) I changed the bike to a pogo stick! The rom also comes with a VBA, a gameboy emulator. To change the controls on the VBA go to options in the top of the screen, the joypad, then configure joypad. To load a game, go to File, then open, the go to the .GBA file you downloaded.
Here are some tools to help you get started.
(Sorry, Whack a Hack is a spanish website, but they do have some great tools.) Pokemon Leafgreen Is downloadable Here. The greatest of these are Advanced map, and Overworld Editor. (I added a link to OE cuz it is not in Whack A Hack.) There is one problem with hacking maps and people, once you change it, you have to start a new game to see it.
Tips for game above, assuming you are going to try it out, which i hope you do:
There is a BICYCLE Right under the stairs of the bottom floor when you start the game (Shown in pic).
I changed it to a Pogo Stick.
Viridian forest is hacked like crazy.
And pick shroomish as your starter.
Rules:
1. No Flaming Spamming, ect.
2. No second rule.

Oh, and Diamond Pearl and platinum is unhackable with any of those tools listed in whack a hack.

Members:
SlyBash