For the NYC BigApps contest, CartoDB is one of the APIs that can be used. In this demo we show you how to use CartoDB together with data from NYC Open Data portal to have an API to find the closest bathroom in NY. Great for mobile applications.
Highlighting a CartoDB/Vizzuality funded contribution to the PostGIS open source project, this video shows how we are using the new Indexed nearest neighbour search in CartoDB to quickly spatially restrict results in our maps in CartoDB. This functionality will be coming soon to all CartoDB users!