Yes
DSi and Wii points were merged together into Nintendo Points, so in theory a DSi points card should work on a Wii, depends how old the card is.
yes you can
no
A Dsi and wii card together costs about $20.00 in Canada and gives you 2000 points to use in wii shop channel and Dsi shop channel!
DSI points are the same as WII points. WII points cards are sold at gaming stores, Walmart, Target, Kmart, etc.
The SD card will work on the Wii but the information stored will not work (with the exception of pictures)
Yes.
you could buy a Nintendo card at like target or 7-11 it works for dsi/wii
you register them at the wii or dsiware shop not on club nintendo.
Game shops such as GAME sell them. What you want is a 'Nintendo Points' card, it will work with a DSi, 3DS or Wii, crediting the account with points or cash, whichever they use.
Yes, the DSi (and XL) use the same memory cards as the Wii does.
Unfortunately, no.