Remember the legendary Predator movie with Arnold Schwarzenegger? Those Predator aliens had this thermal view feature so they could their prey even in complete darkness, let's Photoshop it.
Not your average pixel effect tutorial, let me show you a nice little trick where you apply the normal square pixelated effect and turn it into checkered, diamond looking photo pixels.
If you like the Lords of the Rings movie trilogy, then you might also like this Photoshop tutorial, where we will make a dramatically red sky on a random photograph.