http://www.xmission.com/~hastur/magnets.html
I've seen one of those. That was by far the best mockery of the Jesus fish I've seen to date.
The Christian fish were first, and if my memory serves me right, it's a symbol of the fish-procuring miracle he pulled once.
I dated a crazy reborn christian for a while (Just kinda happened in the middle of the relationship... she was a nut, but hot), and I learned a bunch of stuff that really weirded me out about christianity.
Christianity is a cult. A very well-established cult, but a cult nonetheless. I mean no insult by that statement, but by definition, it is.