Using the Textural Information of a Photo to Create a Custom Border

Photoshop CS5 and later editions contain a feature called Refine Edge which is used refine selection and mask edges.

This video takes a look at how the parameters of Refine Edge (also called Refine Mask) can be used to create grungey frames around a photograph.

These are custom borders in the sense that they are created using the textural information inside the image, so each photograph will produce a unique edge.