I posted this over at my own blog first and was planning on leaving at most a link to it here, but in solidarity with AL I'll post the whole thing.
While I see no good reason to deliberately insult people's beliefs simply for the sake of insulting them, there are pre-eminent reasons to stand up for our own belief, and to take a stand against threats of violence, against attempted intimidation, even by a minority within a community. Indeed, that is all the more reason to not be silent: We cannot let a violent minority of any faith or community determine the terms of debate, and effectively hijack it and become its de facto spokesmen.
It is simply not true that depictions of Mohammed have not been allowed in Islam, as the above pictures demonstrate.
If we do nothing, and if moderate, reasonable Moslems do nothing, then our mental image of Mohammed must become this: