of course the Pokemon league
you get secret potion from Cynthia after you chase galactic grunt in pastoria city
trade from leafgreen
In Pokemon Diamond, Pearl, and Platinum,(for the nintedo DS) Cynthia's grandmother can be found in celestic town, which is located on next to mount cornet (it should be on your map). I believe that her grand mother is also the elder of the town if that helps you.
you can find cheats for it at gamespot.com or supercheats.com.
go to www.codejunkies.com and www.supercheats.com to find out AR Pokemon Diamond/Pearl codes for the DS
You find Nuzleaf at Route 229 but you need to have Pokemon Ruby inserted into your DS.
Pokemon pearl ds card is smaller then a action replay
you tern on your ds and tap Pokemon pearl
You can't find an actual Mew in Pokemon pearl You'll either have to migrate mew,or use action replay
at the oreburgh mining museum:)
The GBA slot is on the bottom of your DS.
In order to get stantler in Pokemon Pearl, you have to beat the game first. Then, I think that it is on the island on the far upper right corner. Take a boat by snowpoint city after beating champion (Cynthia) to get to the island.