Pocket Streets is a companion application to Streets and Trips or Autoroute or Mappoint.

Pocket Streets is available for the Pocket PC and Smartphone.

Microsoft does offer Pocket Streets 2005 maps or Pocket Streets 2004 maps on their site.

Links:

About Pocket Streets - Install or uninstall Pocket Streets, Export and copy a map for Microsoft Pocket Streets, Troubleshoot Microsoft Pocket Streets