Trevor Paglen is one of the most interesting new voices to appear in geography recently. He received his PhD from Berkeley, where he was initially supervised by the late Allan Pred. He is also an artist. He has several books out, including most recently Invisible: Covert Operations And Classified Landscapes, which includes photographs taken during his research. Previous work looked at the CIA’s rendition flights; secret military unit patches; and the Pentagon’s dark geographies. Last year The Guardian produced a compilation of eight of the images from the Invisible book, entitled Nothing to See Here. There are a few pieces available to download from his website too.