European Union:

Community Research & Development Information Service (CORDIS)

European Environment Agency (EEA)

5 th Framework Programme:
5th Framework Programme web site
Improving Human Potential Programme (CORDIS)
List of Projects funded under the 5th Framework Programme (CORDIS)

6 th Framework Programme:
RTD Beyond 2002  (about future EU priorities for RTD)
European Research Area (European Research News Centre)


Other networks and scientific organisations: 

Access to aircrafts for scientific research:
CAATER
EURASER and EUFAR

Compilation of Atmospheric Observation in Support of Satellite measurements over Europe (COSE)

European Science Foundation (ESF)

European Geophysical Society (EGS)

Ice and Environmental Technology Facilities of HSVA (ARCTECLAB)

Ny-Ålesund Science Managers Committee (NySMAC)

Thematic Network for Ultraviolet Measurements

Access to Research Infrastructures in ENVINET
Several of the participants in ENVINET have ARI-contracts with EU. This enables them to let scientists from other ENVINET-members and the general scientific community in EU, use the stations.   More info about opportunities:

ALOMAR (Andøya Rocket Range)

Bergen Marine Food Chain Research Infrastructure 

Kristineberg Marine Research Station

LAPBIAT (Lapland Biosphere - Atmosphere Facility) 

Ny-Ålesund Large Scale Fascility

Monitoring:

AMAP: Arctic Monitoring and Assessment Programme

CAFF: The Programme for Conservation of Arctic Flora and Fauna, 
  projects.

EIONET: European Environment Information and Observation Network

ILTER: International Long-Term Ecological Research 

Miljøovervåking på Svalbard og Jan Mayen (only in Norwegian so far)
  ("Environmental Monitoring at Svalbard and Jan Mayen")

United Nations Earthwatch: The three global observing systems
   (Direct links; Climate - GCOS, Oceans - GOOS, Terrestrial - GTOS)