>>Something else to add. GPS landing systems will be comming into vogue more and more. GPS radio waves operate around the 1 - 2 Gigahertz range which is close to the mobile phone frequency.<<
Dunno if it's close to the GPS frequency or not, but this was tried as well on my little un-scientific test.
If have two different GPS receivers on board and neither were bothered in the slightest.
Perhaps just lucky...
