A Day at the Ballpark

Original Images
(The crowd is reacting to a man catching a bat while holding a beer in his hand, the other images are of Romney and Obama)

Mask(s) made with iScissor.
(I created a mask for Obama and Romney. I just cut the faces of a couple people out of the image then inserted Romney and Obama into the open space.)

Final Image.

(Obama catching a bat with Romney looking disinterested)
To arrive at my final image I did the following steps in Gimp:

I loaded the background image

I inserted the Obama image as another layer and got it into position

I inseted the mask and filled it in with obama's face

I flattened the image and followed the same process to get Romney