I carry a modified one of these on my keys:



Mine has just the nail file, tweezers, and scissors, but no knife.

Just recently they caught it on x-ray and called a bag check, the first time in about 50 flights. I explained it wasn't a knife, and the TSO opened it all the way up and then passed it with a stern warning that I should pull it out of my bag and send it through separately because they'll catch it every time. Wrong--she is far more confident in TSA's detection ability than seems warranted.

Maybe it seems like a stupid little game, but my little not-a-knife fob reminds me of the waste that is TSA. (Yeah I'm bitter--the bastages made my wife cry.)