My Pokémon Ranch is similar in concept to Pokémon Box, and allows players to transfer up to 1,500 of their Pokémon (if they have the Platinum update; without it the limit is 1,000) from up to eight separate Pokémon Diamond and Pearl Nintendo DS game cards, to a ranch run by Hayley, a friend of Bebe who runs the PC box system in these versions. Here, they can view their Pokémon rendered in 3D, while using their Miis to interact with them.
Players do not need to own Pokémon Diamond, Pearl or Platinum to play My Pokémon Ranch. Players with or without the Nintendo DS game will be given six starter Pokémon and a new Pokémon at the start of each day. Additionally, each day Hayley will give the player requests for certain Pokémon not in the player's Pokédex to be added to the ranch, along with instructions on where to find them in Diamond, Pearl and Platinum. It has also been confirmed that players can obtain a special Mew and Phione.
Source: Wikipedia, "http://en.wikipedia.org/wiki/My_Pok%C3%A9mon_Ranch," available under the CC-BY-SA License.