I don't short stocks, as I am not confident that I can pick a top/bottom of a stock. My strategy is to find companies with a history of reporting great earnings, who have little debt, and great management. I buy those companies in blocks (once again, because I don't know which way the stock will trade) and hope that the market will reward the company in due time. Sometimes I will speculate (I usually lose).
If I was going to short a stock it would be something like a MIKR, TATTF, PNTR, EFUT as they have gone up a ridiculous percentage on no news.