From ebay, a map of the transaction activity on Black Friday 2009 (the shopping day after Thanksgiving).  1 million transaction are mapped in the U.S. over the course of the day!

Activity Level Indicator The color of the point on the map indicates the number of transactions that occurred in the corresponding area.

Data Execution This transaction map was created as a study of the extensive activity that occurs in the eBay Marketplace on the biggest offline shopping day of the year. It is a visualization of all U.S.-based buyer and seller transactions on eBay on Black Friday, November 27, 2009 (12:00:00 AM to 11:59:59 PM EST). Although eBay is an international marketplace, this map is focused on U.S. data, as Black Friday is the traditional beginning of the holiday shopping season for the U.S.

It's an interactive, animated timeline, so you can watch the transactions grow throughout the day and zoom in to specific areas of the country by clicking on the map.  It's a flash animation, but there's a WMV movie file available for download too.

They also did a map of the even bigger 1.4 million transactions on Cyber Monday 2009.

Found on VizWorld