Leave it to this ingenious Goonies fan to craft a concealable, retractable knife out of random pieces of hardware.
Needless to say, this is probably 100% illegal in both California and the People's Republic of New York. Oh... that reminds me. Let me tell you something. On a recent trip to the State of New York, I needed a few tools I did not have with me, so I went to a Sears store to procure them, and attempted to purchase a box cutter so I could open up the clampacks (those impossible-to-open plastic packages). Well, the salesman, though very helpful and courteous (probably a gentleman born out of state), told me he couldn't sell me a box cutter because according to New York State law, those are considered 'concealable weapons', and they were not in stock at the moment, as they were in the process of resupplying with shorter-blade alternatives.
You have to be kidding. A god-damned box cutter is illegal in New York State? Mind you, the Sears store was located near a gun shop, so I went there, and after drooling over some sweet AR-15 rifles, picked up some really cool hunting knives. Seriously, I can buy a semi-automatic rifle, a pistol and a machete at the same shopping plaza, and you can't sell me a box cutter? Isn't it a bit inconsistent?
What's going on with New York lawmakers? Next thing you know, based on their infinite wisdom, having intercourse with a member of your own species will be illegal, but if you are into sheep, no worries there. (Apologies for the distasteful analogy). The good legislators in the New York legislature work in mysterious ways indeed. Or maybe it's just that the box cutter lobby isn't as well funded as the gun lobby. Who knows.