Wow. I posted my reply without reading any responses. Apologies if I offended anyone. I thought someone could become jewish if they did some tests and proved their faith to the appropriate person. I have never had a jewish friend, so not too clued up on it.
I was thinking along technical lines when I considered 'jewish' not a race. I wasn't raised in a lilly white wasp community - there just wasn't a particularly noticeable jewish community.