paulo Can see where you are coming from but surely the elctronics on your average commerical airliner is a bit more complex and sensitive than you average spam can...
Check your car handbook and look for the dire warnings about installing CBs, using mobiles etc and the risks to the electronics... covering their ar$es probably but then isn't that what the CAA is doing?
I trained as a radio officer in the merchant navy and my theory is a little rusty now but can remember the most unlikely things causing total S9 noise across incredible bandwidths.... I used to have a calculator with an LED type display which wiped out everything in the MF band!
I tried to use my Magellan GPS on a trans atlantic flight a couple of years back - it was new toy and I wanted to play - but it refused to lock onto any satellites.. those days pax were welcome on the flight deck and during the chat with the crew we came to the conclusion that the aircraft was a very effective Farday cage and that prevented the signal reaching the receiver. GPS signals are frightenly weak compared with other radio transmissions.
So I guess it's risk outweighs your fun!