Gecko OS (formerly Gecko Region Free) lets you load Wii games from other regions.

Changes:

Loading games no longer requires a second disc spin-up
Added support for the new Homebrew Channel ID
Fixed channel loading to use the selected hook type, instead of always using the VBI hook
Improved the 002 error prevention method for channels
Add support for using cIOS for rebooter
Fix dol/elf loading
Add support for System Menu 4.2
Bug fix for poke function in gameconfig.txt (thanks to WiiPower)

http://wiibrew.org/wiki/Gecko_OS