Scitable is a collaborative learning space for science undergraduates, sponsored by Nature Publishing Group. This beta website deals with all aspects of genetics: chromosomes, evolution, inheritance, diseases, society, genomics & nucleic acids.
Muse is a social utility that connects you with Internet2-enabled technologies and educators in your region and around the globe. Learn how next-generation Internet applications are being used everyday to inspire educational excellence.
Wikipedia Collaborations and Portals: One can find Science and Technology Collaborations from the page: http://en.wikipedia.org/wiki/Wikipedia:Collaborations . The Natural & Physical Sciences portals can be found: http://en.wikipedia.org/wiki/Portal:Contents/Portals#Natural_and_physical_sciences. All Science Portals in Wikipedia.
More specialized groups:
Science Community for those interested in cell signalling sponsored by the AAAS, this site provides a Directory for the sharing of Events, Meeting Reports, Forum, E-Letters, and Presentations.
BiomedExperts - the first literature-based scientific social network - brings the right researchers together and allows them to collaborate online. Collexis provides the BiomedExperts social network free of charge to researchers worldwide in an effort to increase collaborative biomedical research for the common good. Analyze the expert profiles of more than 1.4 million scientists.
Labmeeting biomedical. Searches PubMed, Google Scholar, and the Web.
MySciNet Scientists and science students building connections for success. Science (AAAS)
CTSciNet Clinical and translational science network. Science (AAAS)
Communicating Science to the public. AAAS (American Association for the Advancement of Science)
http://sciencestage.com Go to this site for finding science-related videos. One can browse by broad subject area.