The Speed Gamers had just started raising money for some kind of disease ( http://en.wikipedia.org/wiki/Amyotrophic_lateral_sclerosis ). They want to catch all Pokémon from Bulbasaur to Celebi in RBYGSC. Do anyone know how do they want to do it? :D :D :D Without external trades, and possibly without events... :D
Well there is the Mew Glitch in R/B which will let you catch Mew in the wild. But I don't know about Celebi because there is no way to encounter it without an external influence.