Recently I needed to some GIS data in GeoJSON format but couldn't find any pre-existing files, nor a repository of such. Following Mike's "Lets make a map" tutorial
http://bost.ocks.org/mike/map/ I was able to extract the data from NaturalEarth shapefile :)
As way of contributing back to the community, I've created some GeoJSON files (sorry no TopoJSON) for regions derived from specific attributes in the NaturalEarth ne_10m_admin_0_map_subunits shapefile. Each file has the shapefile attribute table maintained within.
Maybe the community could create a repository of both GeoJSON & TopoJSON of common regions and countries.
continent
Africa
Antarctica
Asia
Europe
North America
Oceania
Seven seas (open ocean)
South America
region_un
Africa
Americas
Antarctica
Asia
Europe
Oceania
Seven seas (open ocean)
region_wb
Antarctica
East Asia and Pacific
Europe and Central Asia
Latin America and Caribbean
Middle East and North Africa
North America
South Asia
Sub-Saharan Africa
subregion
Antarctica
Australia and New Zealand
Caribbean
Central America
Central Asia
Eastern Africa
Eastern Asia
Eastern Europe
Melanesia
Micronesia
Middle Africa
Northern Africa
Northern America
Northern Europe
Polynesia
Seven seas (open ocean)
South America
South-Eastern Asia
Southern Africa
Southern Asia
Southern Europe
Western Africa
Western Asia
Western Europe