Call your lender before he calls you...

Here's a nice overview from the Times about how to react if you're getting behind on a mortage or if your ARM is set to adjust. Here's an critical excerpt:

But know this: lenders do not want to get stuck with a property. They have to maintain it and then try to sell it on the open market, usually at a loss. Some industry analysts say that it costs a bank an average of $40,000 to foreclose on a loan. That amount gives the borrower that much more room to negotiate.

If possible, keep your wits about you. One of the toughest things about a potential foreclosure is that human tendancy to ignore or not deal with negative information head-on. Deal with it! These situations have solutions.