Force shutdown on a Galaxy Nexus? Similar to this question: How to force Samsung Galaxy Tab to shutdown?), how can I force my Galaxy Nexus to shutdown?

I can see that it is still on because I've got lightflow installed and the status LED is flashing. However none of the buttons are waking up the screen, so it is pretty much frozen. I've tried holding down the power button for 60s but its still on! :)

Thanks!
The easiest solution would be to simply remove the battery. As far as I know, holding down the power button on the Galaxy Nexus doesn't force it to power down.