I know guys who borrowed from their own 401k plan. You pay back interest but you are paying it to yourself. And that money is pre tax money too. Guy I work with just bought a new truck that way. He figured up how much would need to come from his check each week and he increased his weekly contribution to offset the loan. It is like 8% loan I think, but like I said he is paying it to his own account ( I don't really understand the point of that??) and the money is taken from his pre tax income. Maybe some would say that not a good idea ..should leave that money alone but to me it seems like a decent option as long as you don't go overboard.