When I became a FT'er, I quickly learned that it's easier to stuff my keys, pocket knife, etc. into my carryon that goes through the X-ray machine than it was to empty all my pockets into the plastic dish at every check point.

I carry a fairly large knife, btw. It's a Benchmade one-handed locking folder with a blade length of 3 5/8". I verified that the FAA allows blades shorter than 4" on board, and only once was I stopped and hassled because of the knife; a guard in CLE actually had to get a ruler out to measure the blade while I watched...