A: A correction is when it happens mostly to the other guy's portfolio, a crash is when it happens mostly to yours.
About a month ago I mentioned that the introduction of the various commodity related ETFs could be a signal of a top ('Lessons from the Internet bubble.'), and that's looking like a reasonable call these days.
Again, I tend to think in energy stocks that we may see a medium term top, with more upside ahead, but there are no guarantees.
In terms of watching my stocks, I am looking for them to find support levels at the 20 or 50 day moving average, and I am keeping an eye on volume.
I also have a shopping list which I'm watching to see how they behave and if I find an entry point I like. Candlesticks are a helpful way to identify possible reversal points.