I recall someone here mentioning that the programmer Steve Gibson -- the guy who wrote the Spinrite utility -- had gone low-carb.
Anyway, I took a look at his site, and he now says on his newsgroups that he's working on hardware/software to make a "ketosis breathalyzer".
The ketostik, of course, show how much acetoacetate is in urine, but that disappears from urine over a few weeks as the muscles get used to taking it up and using it for fuel. So Gibson has decided to look for acetone instead.
GRC News Server Temporary Gateway (read only) - KetoFlute Project