European Commission - Regional Policy (Inforegio):  http://ec.europa.eu/regional_policy/index_en.htm
European Commission - Environment (Climate change control campaign): http://ec.europa.eu/environment/climat/campaign/control/additional_en.htm

International organisations

OECD (Regional, rural and urban development)
http://www.oecd.org/about/0,2337,en_2649_37429_1_1_1_1_37429,00.html
World Bank
http://www.worldbank.org/

Transnational Programmes 2007 - 2013
Central Europe: http://www.central2013.eu/

South East Europe: http://www.southeast-europe.net/

European regions and cities organisations

Council of Europe (Congress of local and regional authorities)
http://www.coe.int/t/congress/default_en.asp
Assembly of European Regions (AER)
http://www.a-e-r.org/
Association of European Border Regions (AEBR)
http://www.aebr.net/
Conference of Peripheral and Maritime Regions (CPMR)
http://www.crpm.org/
Eurocities
http://www.eurocities.org/
European Metropolitan Regions and Areas (METREX)
http://www.eurometrex.org/
Association of Regional Development Agencies (EURADA)
http://www.eurada.org/
Euromontana
http://www.euromontana.org/  

Regional policy research

European Spatial Planning Observation Network (ESPON)
http://www.espon.eu/
Regional Studies Association
http://www.regional-studies-assoc.ac.uk/
European Policy Research Centre, Glasgow
http://www.eprc.strath.ac.uk/eprc/  

Maps
Eurostat (Statistical maps)
http://epp.eurostat.ec.europa.eu/portal/page?_pageid=2254,62718791&_dad=portal&_schema=PORTAL
European Spatial Planning Observation Network (ESPON), Publications
http://www.espon.eu/mmp/online/website/content/publications/98/index_EN.html
European Environment Agency (Graphs and maps)
http://dataservice.eea.europa.eu/atlas/default.asp?refid=2D511360-4CD0-4F20-A817-B3A882ACE323