MichaelMeissner:
Anyway, the electrician got a call from one of his other clients, and mentioned something about a military grade RJ-45 setup (RJ-45 is the cat 5/6 cables used for ethernet cables). I asked him what was a military grade RJ-45, and he said you could pick up your whole computer while it was dangling on the RJ-45 cable. I would imagine that is secure.
Of course, I meant the type of RJ series connectors you could pick-up at your local store (Radio Shack, hardware store, etc...). 
I can believe that the military-grade connectors of any type are more robust and physically secure, but I doubt they'd be as hobbyist budget-friendly as other connectors I mentioned. Unless you happen to be lucky enough to find some at a surplus store...
Edit: I don't think this is quite what your electrician was referring to, but here's the datasheet for Amphenol's "Ethernet Connection System for Harsh Environment". It's a set of accessories to harden the ends of an existing standard RJ-45 cable, but you could easily get a couple hundred sets of normal RJ-45 connectors for the price of a mated pair of the most inexpensive options in this product line. 