There's been talk of Apple ditching Google Maps in favor of some rather unattractive proprietary tiles allegedly laid over OpenStreetMap data. Cupertino could do worse than to look at some beautiful alternatives that have been made freely available by Stamen Design. The Toner style starkly renders everything in high contrast black and white, the Terrain style is attractively functional, and the Watercolor style looks like a cross between an infrared heat map and a 16th-century explorer's sketchbook.
Stamen Design tiles put a beautiful skin over OpenStreetMap data
Stamen Design tiles put a beautiful skin over OpenStreetMap data/
Stamen Design has released three sets of tiles for use with OpenStreetMap data.