Me-thinks Matt is correct. Also, be REALLY careful if you follow some of the advice on that thread - rouning off the splines could really suck. You could try to hit a tire shop and see if their ring of keys has something that will remove them. Good luck.
If there is room in there for a socket over the do a search for removing locking lug nuts without a key. I can tell you that what worked for me was to find the tightest fitting socket over the head of the lugnut, then put a piece of steel (thin) between the socket and the lugnut and hammer it on. Took my locking lugs right off...