Tantric shares his Wii homebrew emulator for Gameboy/GameBoy Color/GameBoy Advance. This brew, Visual Boy Advance GX 1.0., features the following:

• Wiimote, Nunchuk, Classic, and Gamecube controller support
• Custom controller configurations
• SD / USB support
• SRAM & State saving
• MEM2 ROM Storage for fast access
• Auto frame skip for those core heavy games

As for the changelog:

• GBA games now run at full speed
• Menu improvements, with spiffy new background - thanks brakken!
• Fixed L/R buttons - they work now

Further notes from Tantric:

• ZIP/DVD/SMB/GameCube Memory Card support are NOT implemented yet
• The current build does NOT have adjustable frameskip. Frameskipping is set to 'AUTO' and cannot be changed
• While speed is generally near perfect, sound tends to rebuffer as a result of frameskipping, so in-game music may suffer as a result, sounding like a CD-skipping. This does not occur with Gameboy Color games or original Gameboy games, which do not use the frameskip function.

Download: Visual Boy Advance GX 1.0.1