Updated from 8:01 a.m. EDTAn essential metric in valuing engineering and construction companies is the current state of their backlog and how that backlog fares in the current global economic backdrop. By definition, a backlog is the total value of sales and orders by clients waiting to be filled by the company. Generally speaking, increase or decreases in a company's backlog might indicate the future direction of sales and forward earnings. Right now, there are a bunch of companies whose current backlog is substantially higher than the entire value of the company. This makes them prime takeover targets, as future contract orders and sales will more than cover for the value of the firm, plus any additional premium a bidder might make. This group does not include any financials, so no Washington Mutual ( WM) or Wachovia ( WB), and there aren't any tech plays such as Apple ( AAPL) or Microsoft ( MSFT), but there are some real opportunities here. To read more, please click here.