At the end of October, there were 27,874 pending foreclosures in Maricopa County. (Back in the summer of 2005, the total inventory of homes for sale was around 5,000. Today it's around
Trustee's sales hit 4,587 in October, up from 4,378 in September.
UPDATE (November 26, 2008): Updated the inventory number to October 21, 2008, which is down from a peak of over 50,000, but which has been climbing back up from a recent low of just under 26,000 at the beginning of August 2008.