The 2 January issue of Science has two articles that might be of interest to readers of this forum. The primary article is "Broadband Invisibility by Non-Euclidean Cloaking" by Leonhardt and Tyc. The second is a perspectives commentary about that article, "Cloaking with Curved Spaces" by Nicolet and Zolla. In summary: It's been shown that geometric transformations of space can distort light beams so that they avoid a bounded region, and any geometric transformation of space can be translated into optical properties. The problem then becomes how can one build materials with the required optical properties.