somebody sent me a link to Stamen basemaps. The page includes a link to make it work with ArcGIS Desktop that allows you to download a ".pkinfo" file.
But that .pkinfo file is not recognized by ArcMap 10-1 nor ArcCatalog 10-1. And I cannot do anything with it in Windows Explorer. The Help doesn't say anything about .pkinfo files.
there's an old forum post that mentions support in 10.1 but I haven't been able to figure out how to make that work yet.