Research group at the University of Pittsburgh with links to books and software on probabilistic, decision-theoretic, and econometric graphical models http://www.sis.pitt.edu/~dsl/
Main association for belief network researchers. Runs the annual Uncertainty in Artificial Intelligence (UAI) conferences, and the UAI mailing list. http://www.auai.org/
Probabilistic reasoning and genetic algorithms for perception, inference and action: Bayesian cognitive and brain models, software for robotics, probabilistic inference engine http://www-laplace.imag.fr
Dynamic Trees are mixtures of tree structured belief networks, and are used as models for image segmentation and tracking. http://www.anc.ed.ac.uk/~amos/belief.html