Beer_n_Tabs:
Another urban myth. When asked, the reason given is always a "filling station blew up in Aamerica/Australia/Germany . . .". No known incident has been recorded.
It's well-nigh impossible to build a fuel/air mix in the open air that will ignite. If sparks caused by metal to metal contact in the presence of an RF field are alleged to be the cause, the max 2 watts from your phone would pale to insignificance beside the 50 watts from the base antenna in the filling station's "tombstone" sign.
If it were easy to blow up filling stations, many other sources of ignition would have come into play by now: hot exhaust manifolds, "sparky" electric door locks and so on.
Shell filling stations typically have T-mobile bases (50W at 1.8Ghz) in them.
As for aircraft refuelling -- ever seen the guys using their radios during the process?