Those of you who fear they've got on the wrong side of Vladimir Putin just might find the Polonium Pen a must-have. Basically a hand-made ion chamber with LED read-out, the Polonium Pen will sniff out excessive doses of the radioactive element in your cocktail, dim sum, or caviar when held over the suspect glass or dish.
There are a few downsides, though. Firstly, the Polonium Pen is extremely fiddly to make. If the wire probe that feeds into the ion chamber touches anything remotely conducive, it won't work. Secondly, the electronics must be shielded by a metallic cover to keep them safe from stray electric fields. And thirdly, the ion chamber is so small that only significant amounts of radiation can be detected. That swings it, then. [TechLib via Hack a Day]