Can i get a new ipod?

i got a ipod touch 3g 8gb, in December, and it is kinda having trouble. what i mean by that is when i open a app, sometimes it freezes, and then goes back to the main menu screen. other times its just plain slow. is there somewhere i can exchange it for a new ipod touch 3g, or better, the 4g? please answer as quick as possible, its annoying me so much!