Researchers at Yahoo have developed a GPS algorithm that allows users to choose a route between two points based on beauty rather than the time or distance it takes.
In order to determine the most "beautiful, quiet, and happy" journeys researchers used UrbanGems, a website that asks users to pick between photos of areas in London and Boston that they found to be the most aesthetically pleasing.
Very interesting idea. My better half prefers driving the less boring routes, and such a system would make her journeys more fun. Need more gasoline, though.
And if this was tied to police databases (even incomplete ones like Chicago's), it could help you pick a safer route. Although IIRC somebody got in trouble with a smartphone app that did that--some spokesmen were afraid visitors would avoid large chunks of town. Of course if visitors wanted to buy drugs it might bring them in.
I assume there already exist path-finders that minimize trips that include particular landmarks. (Maybe not always absolute minimum; the traveling salesman problem can be hard if there are a lot of points) If you weight the connecting roads by beauty (which is seasonal), you could have a very nice trip planner.