i was playing my pearl version and train some pokemon right. when i when to look at them (the status page) on the bottom right hand side of the picture of the pokemon, most of them have this smiley face. what is this? anyone know?
EVs stand for Effort Values, which are obtained by defeating Pokemon. I believe they are explained in the FAQ. And once there's a Smiley Face, Pokerus can not be transferred to other Pokemon.
Like jman said, it means they get doubled EVs (Which are explained in the compiled 4th gen guide, stickied in the S&M section.). Unless you plan on playing compettively there's no need to worry about them.