I'm an engineer with a bit of experience of this sort of stuff.
Your cellular phone cannot blow up a filling station. Filling stations are designed not to blow up, for a start. Try your hardest, you won't be able to do it. It really is an urban myth. Soak your phone in petrol, set light to it, throw it in your open petrol tank, and you're in with a chance of making a nasty mess of your car. That's it.
I'm with apaddyinuk: within 2-3 years, there will be local GSM cells on civil aircraft that will let you use your own mobile on the plane and we'll all get the "I'm on the plane, dear" bore next to us. The only satisfaction we'll get is knowing that the silly sod is paying the airline through the nose for it, just as he does if he uses an airphone now (that magically doesn't interfere with aircraft systems). Could money be an issue in all of this?
I challenge anyone to produce scientifically valid evidence of exploding filling stations or screwed up avionics (NOT anecdotal) caused by cellular phones.
Buzzing in speakers excluded
