The attempted bombing of Delta/Northwest 253 on Christmas Day was not the first from the Islamic terrorists nor will it be the last. Since I am a pilot, I have had people ask what can a passenger do onboard an airplane to help thwart a terrorist attack. Having personal experience with a few events myself, as well as reading articles and hearing stories from other crewmembers, I can give you some information which might assist you in dealing with a suspicious passenger or situation.
As Robert Novak said - "Always love your country - but never trust your government"