The idea

I opted for a humorous artifact, and what is more humorous than superimposing the professor’s face onto images to make for ridiculous scenarios. I chose this image because it's particularly intense, and the intended juxtaposition of the terminator's machine face with Noah's smiling one struck me as very comical.

The execution

I started off with this photo: As you can see, the contours are already superimposed. I then used gimp to use the extracted mask, to select Noah's face to yield the following snippet: I followed this by rotating the selection, cutting it in half, and pasting it into the terminator picture.

The half-face ended up over-filling the human part of the terminator's face, so I had to scale the selection down slightly to make it fit.

The final steps

The next step was to make the fusion more believable. I achieved this by a combination of smudging the region around the middle of the face, and by darkening the middle of the half-face. The smudging achieved the visual effect of the underlying metal face peeking through, which is consistent with the battered condition of the terminator's face in this shot. The darkening lessens the dramatic difference in lighting. These manipulations ultimately yielded the following artifact:

It's still pretty awful.