RetroZone have created an adapter that allows you to do so.

We've been told through various sources that we can use GameCube controllers, as well as the classic controller on the Virtual Console. However, this isn't quite the "retro" experience that we all crave.

Luckily, RetroZone have come to the rescue on this one. Those ancient NES and SNES controllers can be put to use once more, thanks to a new adapter that these folks have created.

Using the RetroZone adapter, you plug one end into the GameCube port, and you plug your controllers into the other end. Thus, you are now able to play NES or SNES games in a true retro fashion!

Excellent stuff.

For more information on this adapter, and other RetroZone products, visit here