ArcticDEM is an NGA-NSF public-private initiative to automatically produce a high-resolution, high quality, digital surface model (DSM) of the Arctic using optical stereo imagery, high-performance computing, and open source photogrammetry software.
The goal of this initiative is to develop a digital data base that contains all available bathymetric data north of 64° North, for use by mapmakers, researchers, institutions, and others whose work requires a detailed and accurate knowledge of the depth and the shape of the Arctic seabed.
The Antarctic Digital database (ADD) is a compilation of medium scale topographic data for the continent of Antarctica. It is derived from a wide variety of sources, and aims to provide the best currently available data in all areas. The site has been revised as of June 2012.
A web site from the National Geospatial-Intelligence Agency (NGA) which allows you to download files of U.S. Board on Geographic Names (BGN) approved names for each country. There is a separate database for Antarctica.