Reaper

I've been wondering for some time now, but what the hell is the point of those passwords/keywords in the naruto anime. Can japanese viewers use that password to get a present of something?
Also what do they mean? cause nobody ever translates them.

Sin

I think it is used to enter a prize draw.

Day Late

Yeah, that's exactly what it is.

Basically, they let all the kiddies know that there will be a prize to be won or a contest or something like that. They tell them that they'll have to gather the passwords or code n' what not, enter them and hope to win!

They do that a lot here as well, mostly on 4kids. Just a simple contest for people.