WMD, kitty litter, or Playboy: you make the call

... the radiation in cat litter comes from trace amounts of uranium, thorium, and potassium-40. Glossy magazines and brazil nuts are also culprits. A guy at Oak Ridge measured the gamma-ray spectrum of Playboy magazine.

Scientists at NIST in Boulder have developed a new gamma-ray detector that, they hope, will be able to distinguish highly-enriched uranium from kitty litter.