This is something I've been thinking about for a number of months, and finally got around to putting together. It's a dashboard that shows which direction the Portland market is heading, based on a number of leading indicators. We use the same basic format at the company I work for to track the business (sales, inventory, revenue, units, etc)

There are a number of leading indicators that drive the increases or decreases in housing prices. They basically come down to supply and demand. Supply being the number of homes on the market, demand being the number of qualified, able buyers.
The top part of the chart shows the leading indicators, the bottom half shows the lagging indicators, or the results.
I will keep refining this and adding to it monthly and with it we should be able to predict when the market has hit bottom and is ready to rebound. I don't believe you can predict the bottom of the stock market, but I think we can predict the bottom of the housing market relatively easily. What will be harder to predict is how much prices lag the bottom, and when things actually pick up. We might bounce along the bottom for a looong time.