Why would you? It may well be a profitable trade but it is definately a punt. No less than black/red on the wheel.
To illustrate the point: In Oct '87 I thought I might buy something cheap after the crash so I bought Ariadne. Now most will never have heard of it but it does still exist today. It wasn't Chris Skase's company but similar and had been flying while the bubble built up. Clearly it never recovered while thousands of other solid companies did.
I have made this point before but it is worth repeating: It is a great folly to wait for the "bargains" before buying because, if you haven't been active over a time, you won't be able to differentiate between a bargain and the inflated junk that caused the crash in the first place.
My reading over the weekend confirms that people I respect such as James Puplava have not called a bottom. For the little it is worth, I agree.
If you have some cash looking for a home, gold, the metal, won't let you down. Debt free mid level miners should also be safe. If you don't want resource stocks, and there seems to be many in that camp here look for an industrial with a low debt/equity ratio (banks probably don't qualify) and with a high multiple of EBIT to interest payments. (I don't follow industrials and can't give a lead on good ones) I would avoid like the plague highly leveraged plays who will get into trouble if they can't roll over their debt.