there is 1 in vendurof town:)
contest hall
In Slateport City, the contest hall is close to the northern exit, just to the left of it.
You can't Get one to keep on you but if you go to a contest hall you can find the berry blenders there
The Move Tutor's house is in Fallarbor Town to the left of the Pokemon Contest Hall.
In lilycove city next to the contest hall there's a house in there is where the GameFreak staff are.
Originally in ruby and sapphire there was 4 contest halls, 3 of them are know battle tents in emerald because now for convenience for the players there is now one main contest hall which is placed in lilycove city all ranks and contests are in this hall.
The Super Contest hall
If you mean a Poke-Block case, you can ask for one in Lilycove City at the Pokemon Contest Hall. One of the girls at the desk will give you one.
Go to the contest hall in lilycove and talk to the lady on the left. She would give you a poke block case.
in fallarbor town but in Pokemon ruby and Sapphire
Go to the contest hall in Slateport City. Once you get there, ask the little girl in the left side of the room, she will give you a pokeblock case. :)
Blend berries at a contest hall. There is a contest hall in Verdanturf, Fallarbor, Slateport and Lilycove.