With the poor investment choices available in many 401(k) plans and the requirement to quit your job in order to get the money out, borrowing the money and buying some gold just might end up being the best way to preserve your retirement funds.
I've considered doing exactly that myself. In the meantime I have everything in foreign stock funds and am hoping the foreign markets won't crash that much.
Borrowing against your 401k is considered one of the worst mistakes people can make. Having a debit card to charge against it would be like that mistake times 100.