Every Map at Once

Leafroulette is an animated map,created by @cartocalypse, which continually pans over the city of Hamburg. Every few seconds, as the map moves across the city, the map layer smoothly changes to a completely different map of the city. In the few minutes that I sat mesmerized by Leafroulette the base map layer switched between a Lidar map, a map of just colorful house numbers, a satellite map, a map of building footprints and a NDVI vegetation map. 

Leafroulette is described by its creator as a "screensaver, CPU burner, background animation thing". It definitely is a fun map to watch moving around in the background. My only regret is that there aren't more background map layers. 

If @cartocalypse is interested in adding a few more map layers then he could always have a look at Leaflet Providers Demo. This map provides views of a number of OSM, MapQuest, Stamen and other map tile layers, all of which can be used with Leaflet.js. The map even includes a JavaScript snippet for each layer so you can just cut and paste the code into your own Leaflet map.

OpenWhateverMap is another map which uses a number of different map tile layers on the same map. This interactive map of the world is created from a random hotchpotch of different map styles. OpenWhateverMap is a showcase for a number of different base map styles that can be used with any of the leading interactive map libraries. It includes base maps designed by Mapbox, OpenStreetMap, Thunderforest,  Stamen and CartoDB.

If you like the look of one of the random map styles then click on the map tile on the map. This will open an information window containing the base map's template URL and the attribution you need to use the style in your own interactive maps.