not at PC at Game boy (No Cheats)
Bfore the elites:
go to route 10,surf there and go to power plant(Zapdos)
go to fuschia city and surf to seaform island (articuno)
go to one island and walk to Mt ember (Molters)

after the elites and get sapphire and ruby:
go to cerulean city and surf to cerulean cave(mewtwo)
catch dogs (bulbasur-entei) (sqritle-raikou) (charmender-succine )

catch more go to www.psypokes.com