Using data from the Internal Revenue Service, Forbes.com recently launched an interactive mapping tool illustrating residential migrating patterns around the country.

More than 10 million Americans moved from one county to another during 2008.   Below is a visual representation of migrating patterns out of Cook County, Il (Chicago).

For real-time interaction with the mapping tool visit:   http://www.forbes.com/2010/06/04/migration-moving-wealthy-interactive-counties-map.html

Source: Internal Revenue Service data. The IRS only reports inter-county moves for more than 10 people, so some moves are not shown on this map.