Google Groups supports the creation of discussion forums for virtual communities to share information via the internet. It is a free mailing list service and can provide open access. Groups can be open or closed. Users can be anonymous. Posts can be made through the web browser or by sending email. It also provides a variety of group management functions. Google Groups archives past posts/emails.
Wikipedia entry about Google Groups: http://en.wikipedia.org/wiki/Google_Groups
WMO metadata & data interoperability: http://groups.google.com/group/wmo-ipetmdi?lnk=srg
Digital Curation: http://groups.google.com/group/digital-curation