Applied Probability Society - A subdivision of the Institute for Operations Research and the Management Sciences (INFORMS) concerned with the application of probability theory to systems that involve random phenomena.
The Applied Probability Trust - The Applied Probability Trust is a non-profit foundation for study and research in the mathematical sciences. It publishes research journals, a student magazine and occasional special volumes.
The Collector's Problem and the Two-Dimensional Factorial - In finding a new solution to a classic probability problem concerning the collection of items in a set, a new and useful recursive function has been found, the "two-dimensional factorial."
The Laymans Guide to Probability - An in-depth but easily readable guide on probability theory, covering various aspects of theory with a bias to gambling games.
Math Surprises: An Example - Buffon's Needle simulation and a surprising demonstration of Barbier's theorem about shapes of constant width
Parrondo Paradox - Parrondo Paradox simulation and a demonstration of the ratchet effect.
Probabilistic Learning Activities Network - Probability activities and simulations in the form of applets and spreadsheets. This site advocates a Question/Hypothesis/Experiment approach to learning probability.