There is almost nothing we don't love about Mad Scientist Hut's Ion Chamber Radiation Detector Kit. It's a Macgyver-esque DIY hack, extremely well documented, and it also gives you everything you need to turn a tin can into radiation detector for under $10.
With Geiger counters being relatively expensive and in short supply, this kit offers a inexpensive (and very cool looking) way to get a general idea about the amount of gamma and beta radiation in your general vicinity (alpha can be detected by putting items inside the chamber).
And the fact that Mad Scientist Hut is donating 50% of all proceeds to disaster relief makes us like the project that much more.
Now available on InMojo: Ion Chamber Radiation Detector Kit
InMojo supports the Open Source Hardware Definition v1.0