To multiply items on Pokemon Diamond/Pearl, you need the action replay. Unfortunately, if you have the DSi, the action replay won't work. It only works for the DS. If you want to 'multiply' Pokemon, breed them by leaving a male and female Pokemon in Solocean Town Daycare Center. Possibly, they could lay an egg!
You can't store items on Pokemon Diamond and Pearl, as your bag now can carry an unlimited supply of items.
trade diamond from Pokemon diamond onto Pokemon pearl
You cannot clone Pokemon and items on diamond and pearl and platinum, but you can in emerald!
You trade Magmar from Pokemon pearl,diamond,or platinum to ether Pokemon pearl,diamond,or platinum.
THE POKEMON THAT ARE NOT FOUND IN DIAMOND AND PEARL ARE:MANAPHY PHIONE
diamond
You can get Palkia in Pearl, otherwise you have to transfer Palkia from Pokemon Pearl to Pokemon Diamond.
some of the Pokemon are different such as diamond has dialga and pearl has palkia some of the Pokemon are different such as diamond has dialga and pearl has palkia
No, you can't catch Deoxys on Pokemon Diamond & Pearl unless you have cheats. You can transfer it from your GBA to Pokemon Diamond and Pearl though
Item BoxesYou can't store items in Pokemon Diamond and Pearl. The Item boxes were only for the older games. Now, to store items, you can just give the items to Pokemon stored in the PC.
Palkia is the legendary Pokemon in Pearl, and there is also various Pokemon found in Pearl, but not in Diamond. Diamond has some, that Pearl doesn't have.
You can't because you can't dive in Pokemon diamond or pearl.