at the Cooper-Hewitt National Design Museum
Make sure to check all the links on the Van Cleef & Arpels exhibition pages (Video, Innovation, Transformations, Nature, etc.) to view selected items. The last time I was in New York, the Cooper-Hewitt was beginning a major construction project. It was impressive to visit the Andrew Carnegie Mansion, which is the museum's main building. It looks like parts of the museum are in full function with the Van Cleef & Arpels exhibition. The renovations should be completed by 2013.
Video on the renovation plans