No one can accurately predict the stock market's bottom or whether it will recover more than it has lost, but I personally would rather bet on humankind than against it.
So, I will continue to invest in the stock market without trying to time it: Whenever my checking account has five thousand dollars more in it than I need, I invest that in Vanguard Total Stock Market ETF, which offers broad stock diversification at an extremely low fee--0.07% plus the rock-bottom $4-per-trade commission charged by Sharebuilder.
That approach to investing means that over time, I end up owning more shares bought when prices are low than when they're high. And I don't have the stress of trying to do what even most professional investors can't do: time the market and pick individual stocks that will beat the market.
Of course, before investing, everyone should have at least a few months worth of cash reserves in a money market account to allow for emergencies.
I want to be clear: I am not a professional financial advisor, and your individual situation may warrant a different investment strategy than mine, for example, if you need to insulate your money against wide short-term swings. So, it's typically wise to consult a trusted financial advisor, perhaps showing this blog post to him or her.