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

Changes:

Moved rebooter to a menu item
Fixed a bug that prevented the codes and patch folder from being found if in data/gecko
Fixed a bug that caused a core dump if background.png is in the root directory of the SD card
Language and video mode settings from WiiRD are now used if a game is started from WiiRD
Fixed a rebooter bug that caused the currently inserted game disc not to show up in the disc channel

http://wiibrew.org/wiki/Gecko_OS