Hmm, forgot about this thread.
It's funny seeing all of you sitting at home trying to justify this or say it isn't so. I'm telling you, the proper term is gaikokujin. The term gaijin is not a colloquialism or indifferent slang. It is not "convenient and funny ^^". it is just plain rude; fightin' words, if you say it to my face.
And yes, some foreigners idiotically call themselves "gaijin," but some black people call themselves "nigger" too.