It looks like a pretty random form of triangulation. Probably just done by hand.
Just draw a bunch of dots and start making triangles to connect the dots!
Awhile back we talked about Delaunay triangulation on GD.SE...it's a lot more mathematically rigid than the picture you reference but it creates a very similar effect. There are some tools available to make it happen in Illustrator, or you could create your own script to do it yourself (I've done this in a rudimentary way so I can definitely say it's possible). Not sure about doing the same thing in Photoshop, though.