
Having travelled to both the UK and the US, my border experiences at the UK were much worse. That said I was living in the UK on a working holiday visa (and travelling a lot) and only one of my US trips was post September 11.
A sat nav, on the other hand, is designed so that you don't have to touch it once it's set up. Its voice instructions are designed so you don't usually have to even look at it. If you do have to look at it, it's designed so that a glance is sufficient.
Just because you don't have to look at it doesn't mean people don't. I was in a car accident where the taxi driver was so preoccupied with looking at his sat nav he failed to check for traffic at an intersection. Fortunately no one was seriously injured but the other persons car was probably a write off.
That's really an endorsement for porting Linux apps to Windows.
With your bare hands?!?