Please feel free to add to this list or start a discussion about your own experience in SL.
MIT Second Life wiki: https://wikis-mit-edu.ezproxyberklee.flo.org/confluence/display/SL/Second+LIfe+at+MIT+Home
(contains useful links etc)
The New Media Consortium is one of the main advocates of educational/research applications of Second Life. Here they provide a good introductory video to give you a glimpse of a SL workshop they held on the topic of creativity. http://sl.nmc.org/2007/12/16/oldie-but-goodie-video/
IBM Second Life collaboration page: http://www-304.ibm.com/jct09002c/isv/marketing/industrynetworks/benefits/second_life.html;
Second Life Science: http://theforcethat.blogspot.com/2007/02/virtual-science-in-second-life.html
(see bottom for links to the Second Life International Science Museum)
Second Life Portugal: http://www.slportugal.com/