ACM SIGGRAPH
Siggraph mission is to promote the generation and dissemination of information on computer graphics and interactive techniques. Its purpose is to foster a membership community whose core values help them to catalyze the innovation and application of computer graphics and interactive techniques.
http://www.siggraph.org/cgresources/learning.html

Rhizome
Rhizome is an online community space for people who are interested in new media art. Its activities focus on: presenting artworks by new media artists, critics and curators; fostering critical dialog; and preserving new media art for the future. The Art Base? is Rhizome's online archive of Internet art. It contains both links to net art projects on the web, and also net art projects than have been cloned and uploaded to the Rhizome server for preservation. Much of Rhizome's activity takes place on email lists.
http://www.rhizome.org/links/7.php3