Datamaps is intended to provide some data visualizations based on geographical data. It's SVG-based, can scale to any screen size, and includes everything inside of 1 script file. It heavily relies on the amazing D3.js library.
Out of the box it includes support for choropleths and bubble maps (see demos), but it's not limited to just that. Its new plugin system allows for the addition of any type of visualization over the map.