Link: Google - public data

Datasets are limited at the moment [only going live in its current form recently] but I am sure that the datasets will be added to over time.

Datasets I find this evening:

World Development Indicators (subset): World Bank
OECD Factbook 2009 (subset): OECD Factbook 2009
Unemployment in Europe (monthly): Eurostat
Harmonized Index of Consumer Prices in Europe: Eurostat
Minimum Wage in Europe: Eurostat
Unemployment in the U.S.: U.S. Bureau of Labor Statistics
GDP and Personal Income of the U.S. (annual): U.S. Bureau of Economic Analysis
Retail Sales in the U.S.: U.S. Census Bureau
Population in the U.S.: US Census Bureau
Sexually Transmitted Diseases in the U.S.: NCHHSTP powered by CDC WONDER
Mortality in the U.S.: NCHS, OAE powered by CDC WONDER
Cancer cases in the U.S.: CDC, NCI and NAACCR powered by CDC WONDER
Education Statistics of California: California Department of Education.