I'm at the Wi-Fi business development summit in Milan. I'm in a theatre in a conference centre owned by IBM. And I'm on Wi-Fi of course.
I notice that my phone has no signal. Not a poor signal, but a completee absence of GSM. the explanation is pretty obvious - the walls are metal. This is deliberate. No one at the conference so far has had to say "please turn off your mobile phones", because IBM made the whole theatre into a Faraday cage.
So the temptation is clear: I really should turn the sound up on the laptop, and get someone to phone me on Skype. I won't of course, but it would be worth it, to see the IBM staff's double take, and to have the first phone to ring in the centre.
On the other hand, I could ring someone else's Skype. How about Nico MacDonald who is sitting at the back? Of course, he too has his volume down. Ah well, back to the conference session.