Everyone's 410k is down. If you don't retire within the next 10 years or need cash within the next 5-7 years, i wouldn't even worry about it. Ride it out. Markets always rebound, this time it's just going to take longer.
If you can wait, then the best thing is probably to forget that you even have a 401k and look at it again in a few years. :imho:
M.