Easy to forget when this is something you carry in your pack all the time. Unfortunately you can only put it in your checked baggage - and the way I travel lately, I don't check any baggage (they are good a losing stuff, or damaging luggage - ever watched them how they load it?)

Check this funny video about airport security:

The new one looks sweet!
But I had (temporarily) lost a knife going through US customs from Canada (on land). They found a knife in the toolbox in my trunk and decided it was a restricted weapon (since it somewhat resembled a butterfly knife). I did get it back though: they diligently returned it to me by mail with a letter of apology saying upon examination, it was not forbidden.