I'm guessing you're a fairly new atheist. You probably discovered Dawkins and Hitchens about a year ago and now feel emboldened to share your atheism with a generally insane religious world.

However, any point you are trying to make, is completely undone by your last sentence. Those anti-semitic cartoons you mention, are simply racist. They are written by racists, to be read by racists.

Now, if we are holding up Racist cartoons, as the ideal for us to meet, then you are woefully off the mark.

Free speech is an absolute right in my view, and the fear of causing offence is not something that should be a concern. But doing things to purely antagonise a section of the population, is not really any better.

I'm not sure what kind of cartoon joke would be made better by drawing Mohamed.