The TSA has banned lighters in both carry-on and checked luggage, so if you are traveling within, to, or from the United States, you will need to leave your lighter at home.
You may be surprised that despite the evolution of security at airports that has been occurring over the past few years that many potential "weapons" are being allowed to go through airport security and may be brought on board. There are various banned items depending on the country you are traveling from, but you may be surprised at what is allowed on board these days.
Did you ever think of your tennis racket as a weapon? Because it is a sporting item, you'll be checking it in. As more governments worldwide take over the task of security screening at airports, it becomes even more important to know before you go or risk having some of your belongings being confiscated, or at least sending you back to check them in.
In a recent CNN article, they reported some of the items still allowed for transport as carry-on in the U.S.. Be aware however, that depending on which country you are traveling to, or in, that the list of allowable items for carry-on will vary.
In the U.S. corkscrews are allowed for carry-on, whereas in Canada corkscrews are only permitted in checked luggage. Toy weapons are banned as carry on in the U.K., Canada, and other countries, but only true-looking replicas are banned in the U.S.. Metal nail files are nearly universally banned, but nail clippers with no metal nail file are not.
Any doubt of what you can or can't bring can be taken away by following the links to some of the government websites about airport security screening. Any further doubts? Then it is a good idea to call the airline directly as they will outline what can/not be brought on board, and can advise you not only about banned potential weapons, but about what the airline considers dangerous goods as well.
