Inventgeek has a fascinating project that uses a webcam and a small radiation source from common household fire alarms to visualize radioactive decay. This could have applications as a source of entropy for a true random number generator.
I started this project with more of an idea of creating a system that would visualize Cherenkov radiation via webcam utilizing a Gamma radiation source and heavy water in some heavy lead shielding to produce the tell tale bursts of blue light. Perhaps hook it up to the LCD window kit system we did and display it on the windowed screen. When I decided to ramp up the project and also was experimenting with other types and sources of radiation for the project I stumbled across a myriad of new ideas for possible systems with some far reaching and profound results. While this write-up is just discussing in detail the implementation of this apparatus for ones personal amusement via screensaver, there are other far reaching possibilities for this system I will discuss later in the article.