Bragg's Law Applet (Konstantin Lukin, SUNY Stoneybrook)
X Ray Diffraction Resources & Information (Online X-Ray Technician Schools)
X-Ray Generation (University of Kansas), also explains Seigbahn notation (K alpha 1, K alpha 2, K beta 1, etc.)
Titanium Dioxide, rutile and anatase crystals (Polymer Science Learning Center)