Definitely the distraction caused by radio/intercom noises when a mobile is in use are a flight safety hazard. Some of the noise-cancelling headsets in use are particularly sensitive to this effect.
Also I've known the 76 Aft Bag Smoke warning to illuminate when there's a laptop computer close to the detector in the Baggage Bay; annoying when you have to land to investigate.
I've never seen any effect on the digital engine controls but I've had the GPS unlock when some bright spark can't bear to be disconnected for a few minutes. Also annoying in bad weather...
Finally some of us believe that strong rf from an outside source (ie a cellphone network) MAY be able to trigger the floats after they have been armed; Sikorsky denies this but I suspect they have not fully tested for this possibility. I stress this is not from an individual mobile but from a nearby cellphone network; interference can sometimes be heard on radios and i/c's around this spot too.
Very welcome back Nick; any comments on the above?