The clever men and women at Rare actually figured out a way to offer connectivity between Viva Piñata: Trouble in Paradise on the Xbox 360, and the Viva Piñata game on the Nintendo DS. Unfortunately, they figured it out a bit too late in development, and the unprecedented "Three-Six-DS" (say it out loud) connection will not make it into either game.
How would it have worked? Trouble in Paradise on the 360 uses the Live Vision Camera to interpret special codes on Viva Piñata trading cards. The camera's resolution is high enough to even read card codes off of digital screens, like iPods, Zunes (lawl) and portable gaming systems.
According to MTV's Stephen Totilo, Rare realized that codes could be placed in the Nintendo DS Piñata game to allow content to be transferred from the portable to the 360 version. Sadly, this realization came too late in the development cycle of the DS game, and reportedly could not be included. It's the thought that counts, right?