TerryG wrote: Do you do the hovering or vacuuming?
Hmm, it's donkey's years since I saw a hover vacuum (Hoover made one in the 50s/60s - the "Constellation"):
In my case, I Hoover the carpets, Silverline or Aqua-vac the car (or workshop, Rayburn flue etc), Karcher or Daewoo the stairs or fiddly bits (on rare occasions) or, if I am really sad, Vax the computer keyboard/motherboard! A friend insists he (ie his wife) Hoovers with their Dyson
Being pedantic, I don't think something for detecting a particular mobile phone service provider is actually used in car exhausts!!
EDIT: changed the link to show the Hoover - I hadn't noticed that the original picture didn't show correctly (I thought it did when I did a preview!)