Quantum Mechanics: Myths and Facts (pdf), a recently-updated paper on the Cornell arXiv peer-review site. By Hrvoje Nikolić of the Rudjer Bošković Institute in Croatia. [more inside]
Ripple Tank Simulation is a delightful, mesmeric java applet simulation of a ripple tank. It demonstrates two dimensional wave phenomena such as interference, diffraction, refraction, resonance, phased arrays, and the Doppler effect (do try the 3D view). From Paul Falstad's fantastic collection of Math, Physics and Engineering Applets.
Resonata - A Wave Machine [Java]
This cornstarch, it vibrates. (wmv 4MB)