These are phone numbers you can collect in Gold/Silver so you can either re-battle them, maybe even spot some rare Pokémon Swarms! Remember, you can only hold 10 phone numbers including Prof. Elm and your Mother.

Trainer	Location
Bird Keeper Vance	Route 44
Blackbelt Kenji	Route 45
Bug Catcher Arnie	Route 35
Bug Catcher Wade	Route 31
Camper Todd	Route 34
Cooltrainer Beth	Route 26
Cooltrainer Gaven	Route 26
Cooltrainer Reena	Route 26
Fisher Chris	Route 42
Fisher Ralph	Route 32
Fisher Wilton	Route 44
Hiker Anthony	Route 32
Hiker Parry	Route 45
Juggler Irwin	Route 35
Picniker Erin	Route 36
Picniker Gina	Route 34
Picniker Liz	Route 32
Picniker Tiffany	Route 43
Pokéfan Beverly	National Park
Pokéfan Derek	Route 38
Pokémaniac Brent	Route 43
Sailor Huey	Olivine Lighthouse
Schoolboy Alan	Route 36
Schoolboy Chad	Route 38
Schoolboy Jack	National Park
Youngster Joey	Route 30