YAY!!! Le Cricket and I just played for a few hours, it was fun!!! Online is REALLY good.
Wolfy, under the wifi connections you can enter your friends' codes (which is DIFFERENT than your Wii friend code). Then you have options of racing with them and computer people, or with real random people, or creating private rooms with your friends.
My Mario Kart Wii code is 1977-0594-4893. (FYI my regular Wii friend code is 1033-4876-9284-4611). Both people have to enter each others codes to be "friends"
(But I think for the purposes of that game, just entering your MK code will suffice).
(Also, is there any reason why I should NOT have my Wii codes out in the open? Everyone is so secretive for some reason... but both people have to enter each others to do anything anyway)