Your Android Phone Can Now Be A 3DS AR Card notes when Joel used his iPhone as a Nintendo 3DS AR Card, as an application has turned up on the Android marketplace doing just that.

— Looks like somebody was taking notes when Joel used his iPhone as a Nintendo 3DS AR Card, as an application has turned up on the Android marketplace doing just that.
3DS AR Cards is a free app, which gives you digital versions of all the new Nintendo handheld's augmented reality cards. So rather than carrying the things around with you, you can just whip out your phone and use its onboard versions instead.
And if you're worried that confining the cards to a phone's screen will stop you from being able to create GIANT MARIOS, if your tablet device of choice can access the store then you can use the cards on a bigger screen.