Go to the Uranus Zone, and find the merchandise stand opposite the bar, next to the whack-a-mole game, which has 4 "Alien Probes" propped up on the wall next to two Toy Spaceships.
Simply stand in real close and take a pic.
You'll net a massive amount erotica points if your close enough.
In case that doesn't work, you can always pull them off the wall, they are unlimited.
This is also a good place to get the "Mixed Messages" Achievement
Simply kill a zombie brutally, then take a pic of the probes, (for erotica) spaceships (for outtake) the dead zombie (brutality) and another zombie all in the same frame. An easy way to do this is to take the sniper rifle from the roof opposite of the stand, snipe a zombie then zoom in and take a pic.