The Toolbox special in the current issue of Nature discusses the (new) geospatial visualization tools that are available to researchers - such as CartoDB and TileMill:
Zastrow 2014. Data visualization: Science on the map. Nature 519, 119-120. doi: 10.1038/519119a
The article includes quotes from Peter Desmet about the visualizations we made at LifeWatch INBO for our bird tracking network (see previous posts) and the online version even features the interactive bird migration flow visualization we developed for the European Network for the Radar Surveillance of Animal Movement (ENRAM).
You can read the article online here.