Adam showed me an amazing web site on radioactivity. All you want to know about the cool products that contain radiation from uranium are listed here.
My favorite pick
The idea is that you drink the water coming out of this revigator. The radioactive water is exceptionally healthy for you according to studies (see below). Theodore Gray (the author of this web-catalog on uranium) proposes a nice parallel to our current expectations of what is "natural", assuming natural is pure and unharmful. This object came from a time where radioactivity was considered "natural".
The claim that it can't possibly be harmful because it's not a drug or medicine, it's all natural. The "it" being radon gas, which is now known to be one of the most powerfully toxic substances in the world, so toxic that even barely measurable concentrations from natural sources are a problem in many people's houses.
Here is the book that describes the revigator.