Population Statistics - Summarized population trends over time by country and by regions within countries. - http://www.library.uu.nl/wesp/populstat/populhome.html
Population Reference Bureau - Information on population estimates and key indicators for all members of the UN and areas with populations of or greater than 150,000. - http://www.prb.org/
UNECE - United Nations Economic Commission for Europe online statistics. - http://www.unece.org/stats/data.htm
Global Population Data Sets - Population databases for the globe, Africa, and Asia. - http://grid2.cr.usgs.gov/globalpop/
Measure DHS - Data collection for evaluation needs of host countries. Population and facility-based surveys, secondary data analyses, and research using qualitative, education, and gender-based studies. - http://www.measuredhs.com