Laptops
Stringfellow,
you asked: "how about laptops and CD players, what's the issue there? All I can assume is it's down to potential RF interference from their internal components. Could this really be a problem? "
Most laptops emit a surprising amount of RF, but few people think about it because it's not obvious as with a phone, so it's never become a media issue. However, I remember Peter Cochrane, former r&d guy at BT, saying that if anyone who felt they were at risk from holding a GSM phone near their head would logically never let a laptop anywhere near their, er, lap !