Echoing fleshconsumed... don't time the market. It never works. If you feel you need to pull money out of stocks or stop contributing, then you have the wrong asset allocation.
The smart ones just keep putting money in and act as if nothing is happening. They may contribute a little more or a little less than more, but their contributions don't change from their baseline. If you're making your 401k, keep maxing it. If you're (also) maxing your IRA, keep maxing it. If you've been comfortable with 90/10 stocks/bonds for the past 10 years, you should still be comfortable with it unless you're retiring in five years.