All of the solutions so far depend on having a really thick angled border to divide the photos.
To avoid this you'd make a container and skew it. Then counter skew the image in the opposite direction.
Here's a CodePen http://cdpn.io/azvsA, but the gist of it is as follows:
.container {
border-right: 10px solid white;
overflow: hidden;
transform (skewX(-20deg));
}
.image {
transform (skewX(20deg));
}