The batteries only last two hours, but BVS sells other models with longer coverage times and wider ranges.
Most are sold by companies offering spy gear and anti-spy gear, many of which are more than a little shady.
Cell detectors don't change or block cell phone signals, however, so they're legal in most states, unlike cell-signal blockers.
Phone detectors seem like they live on the borderline between the need to keep a digital environment secure and the creepy wish to be able to spy on anyone, anywhere without their knowing.
Several of the same resellers that carry cell-signal detectors also carry covert GPS trackers, cell-phone signal intercept-and-decoders that let you listen in on calls or texts, hidden IP cameras and other systems used mainly for covert, privacy invading surveillance.
Needless to say, that's also illegal, not to mention repulsive, so it's probably best for your police record and reputation as a non-creep to stick to the parts of reseller sites displaying products that aren't quite designed specifically to invade the privacy of others. It's better for everyone that way.
Speaking of which, it's probably obvious what kinds of products are in sections marked "DNA Paternity Testing ."
If it's not obvious to you what would be sold under "Fluid Detection," it's probably best not to check.
Read more of Kevin Fogarty's CoreIT blog and follow the latest IT news at ITworld. Follow Kevin on Twitter at @KevinFogarty. For the latest IT news, analysis and how-tos, follow ITworld on Twitter and Facebook.