I routinely travel with my knitting stuff, which includes several blunt and sharp needles in a needle case. I've never had a problem with it domestically (or at least not recently.) The fact that they are small and mixed in with other items probably disguises them. My knitting bag clearly looks like "a knitting bag," which is usually sufficient. At most, domestic security might ask what I'm working on. A few months back the guy sitting behind me was tying a quilt and had a toolbox with him, including some substantial thread snips.

International is another story, I've found. The tiny airport in Italy we go through gets Very Unhappy about quite a number of things including safety pins and kiddie scissors. I've switched to wood and plastic knitting needles only and use nail clippers to cut yarn. Any small metal items are of a sort that I could stand to lose them if pressed.