2009-01-06 - The Home Machinist forums
2009-01-05 - mCADForums.com
2008-12-28 - rocketryplanet
2008-09-01 - PSICS forums
2008-08-25 - welderzone (213 members, 76 threads, 274 posts, ... got this from an email from cnczone.)
2008-07-05 - di.fm forums
2008-05-17 - Blender Artists
2008-05-12 - INTJ forum
2008-05-11 - Students for the Development of Space
2008-04-21 - Project Polymath (no RSS)
2008-04-19 - MarsDrive (no RSS)
2008-04-07 - Biopunk (no RSS)
2008-04-06 - OpenVirgle (RSS)
2008-03-31 - Propylae / Enter the Agora (no RSS; Mike Trice)
2008-03-17 - BioNMR community (no RSS)
2008-03-05 - SocOfRobots forum
2008-03-02 - Dolfyn (CFD) forums (no RSS)
http://www.sciencemadness.org/talk/ (2007-10-08: no RSS)
http://www.roguesci.org/theforum/index.php username: Humbleman (RSS)
http://forums.studentdoctor.net/ (RSS)
http://www.scienceforums.net/forum/ (RSS)
http://forums.hypography.com/index.php (2007-10-08: no RSS)
--> RSS feeds:
http://www.lab-monkeys.com/forums/ (2007-10-08: this website has died a painful death for quite some time, overtaken by spambots)
http://forum.physorg.com/index.php (main site RSS)
http://www.physicsforums.com/ (RSS)
http://4hv.org/e107_plugins/forum/forum.php (2007-10-08: no RSS)
http://www.everything-science.com/sci/Forum (RSS)
http://www.eng-tips.com/ (2007-10-08: no RSS / still ads)
http://forums.philosophyforums.com/ (RSS)
http://conworlds.info/cwbb/ (2007-10-08: no RSS)
http://www.advancedphysics.org/forum/ (2007-10-08: dead?)
http://www.plastictalk.com/forum/ (2007-10-08: no RSS)
http://www.electronics-lab.com/forum/ (2007-10-08: dead?)
http://www.avsforum.com/ (RSS)
http://forum.wolframscience.com/ (2007-10-08: no RSS)
http://chemicalforums.com/ (RSS?)
http://www.thenakedscientists.com/forum/ (2007-10-08: no RSS)
http://sciforums.com/ (2007-10-08: no RSS)
http://www.nitrogenorder.org/cgi-bin/forum/forum.cgi (2007-10-08: forbidden)
Art of problem solving (2007-10-08: MySQL errors)

http://community.boredofstudies.org/ (RSS)
http://www.thestudentroom.co.uk/index.php (2007-10-08: RSS, but probably not worth the trouble)
http://www.splung.com/phpBB2/index.php ?? (not many users at the moment, though lots of content on the website) (2007-10-08: no RSS)
Dresden Codak / Koala Wallop forums (scifi/transhumanism?) (2007-10-08: no RSS)
Bad astronomy forums (RSS)
Molecular station (RSS)
Sciencefile.org "The science forums" (2007-10-08: no RSS)
prep4usmle.com (RSS)
Biology-online (RSS)
BioTechnique molecular biology forums (RSS)
Xenomed (RSS)
Sciencechatforum.com (RSS)
Newmars.com (2007-10-08: no RSS)
Alcor United (cryonics) forum (2007-09-29: still no RSS; 2007-10-08)
Reform Alcor forums (2008-02-24: RSS; not added)
Immortality Institute forums (2007-10-08: no RSS)
Orion's Arm RPG (no RSS) (2007-10-08: dead?)
Antibody&Beyond forum (RSS)
BrainMeta forums (RSS)
DVXuser.com forums - filmmaking community (RSS)
psyclick.org.uk - clinical psychology forums. (2007-10-08: no RSS)
Physics simulation forum (no RSS as of July 28th, '07) (2007-10-08: RSS?)
MyMathForum.com (RSS)
MathLinks (2007-10-08: no RSS)
PopAstro forums (2007-10-08: no RSS)
ChE Resources (RSS)
Rotary wing forum (RSS)
BioPlanet (bioinformatics) forums (no RSS) (2007-09-12) (2007-10-08: dead?)
Society for Neuroscience forums (no RSS) (2007-09-20) (2007-10-08)
NeuroImagingNetwork forums (no RSS) (2007-09-20) (2007-10-08)
Talk-Polywell (2007-10-13: no RSS)
Memeticai (2007-10-24: no RSS)
On Intelligence (2007-11-12: no RSS)
Open Source Aerospace (2008-02-17: RSS)
Space Fellowship (2007-12-15: no RSS)
Betterhumans.com (2007-12-15: no RSS)
Google Lunar X Prize (2007-12-16: no RSS)
Team FREDNET (2007-12-16: no RSS)
InterPlanetaryVentures (2007-12-28: no RSS)
Trossen Robotics (2007-12-30: RSS)
Roboludens - Eindhoven robocup (2008-01-06: no RSS)
Forex automated trading systems discussion (2008-01-15: RSS)
Quantnet (2008-01-15: RSS)
EcoliHub forum (2008-01-27: no RSS)
The Methuselah Foundation Forums (2008-02-13: no RSS)

http://slashdot.org/ username: the_kanzure (RSS)

Even older from '03 was the DarkBasic community, but no longer does that seem to be of any use. Too, there was once the GameShark community, which has been erased and replaced in the last seven years with something 'worse' (or maybe I only see it clearly now). Gaiaonline.com, too. Can't forget that.

Microbes forum (kind of inactive)
Medscitalk if the registration functionality ever approaches 'working'
Biocompare if they ever remove their ads.
Chemicool (just not lots of activity yet)
Analytical chemistry forums (maybe when the membership increases)
Unpublished chemistry forums
Maybe chemist.pk if the ads and bots are removed.
Maybe Mychemistrytutor.com/forums/ if the registration feature ever starts working.
WebQC forums re: chemistry looks nearly dead, so maybe in the future. (no RSS)
ilovephysics.com forums if it becomes more active and less, dead.
Epidemiology forum if it ever becomes more active (33 registered members, 5 posts, ...)
FreeMathHelp.com- though it's mostly basic mathematics.
StudentDoc.com- kind of small place, no RSS as of July 28th '07, etc.
http://physicsmathforums.com/ - Not much activity?

Not yet added

2007-08-24: osdev.org forums (RSS)
2007-10-14: Copperthermite.com (no RSS) rocketry.