Your best bet is to get a wirless router.
All your connection options are listed here:
hello, i want to get wifi for my wii but, i cant use the LAN adapter because i dont have an ethernet port on my modem,and i have a Mac for a computer
does anyone know of something i could get???
Going wireless is cheap and productive, setup is also easy, just go wireless, can't go wrong with that.
Please feel free to contact me for any SBTourney related questions at:
thanks guys ill try that!