Here are a few places I've been while working on the next links update. More to come as I find them.
bryce stuff - http://azerbryce.site.voila.fr/
More bryce stuff and photoshop - http://www.infinitee-designs.com/Downloads.htm
3D ModelWORKS - Mostly models, freebies left bottom - http://www.3dmodelworks.com/
Model Bank has a free model of the month - http://www.modelbank.com/
Automobile blueprints for modelers here - http://cgworld.ru/modules.php?name=Blueprints
Human anatomy for artists - http://www.fineart.sk/
"Gray's Anatomy of the Human Body" online - http://www.bartelby.com/107/
Modeling reference site - http://www.cloudster.com/VaultLobby.htm
Some characters sets that Pangor let me know about that are free at Planit 3D and elsewhere.
For the Freak and M3 - http://www.planit3d.com/source/Poser/gregor/gregor.html
For V3 - http://www.planit3d.com/source/Poser/msk3d1.html
At PoserPower, a morph to make David a young boy - http://poserpower.com/phpBB2/viewtopic.php?t=41
4BlueEyes - Mostly P5 and above, but some P4 goodies - http://www.4blueyes.com/freebies.php?q=clothes&p=1&rf=barracuda