If you're travelling regularly between your home and Pennsylvania and your office in California, it sounds much easier to just leave a box of stuff (tools, pocket knife, etc) at the office so that it's always there waiting for you, than figure out how to get it to and from the office by plane.

I see the local travel store sells what amounts to cable ties withunique serial numbers stamped in them. Again, TSA can easily cut them off, but nobody is likely to be able to be able to cut one off and replace it with another one having the same serial number.

Finally, I've heard they search you all the more enthusiastically if you don't check any bags.