One part of Windows 7 is the new capability for applications to be location and sensor aware.

There are new standardised API's for an application to interact with location sensors in order to figure out where in the world the user is and there's also API's to determine things like;

• Ambient light
• Orientation

There's a lot more detail up at the platform's home page up here;

http://www.microsoft.com/whdc/device/sensors/default.mspx

and then there's information up on the blogs here;

http://blogs.msdn.com/semantics/default.aspx

http://blogs.msdn.com/jimtravis/

http://blogs.msdn.com/gavingear/

including a sample location-aware application written in WPF here;

http://blogs.msdn.com/semantics/archive/2008/11/04/sample-location-aware-wpf-application.aspx

that makes use of the Virtual Earth WPF control that I wrote up here;

http://mtaulty.com/CommunityServer/blogs/mike_taultys_blog/archive/2008/10/09/10822.aspx

Very cool stuff - there's also the PDC session up here;

http://channel9.msdn.com/pdc2008/PC25/

which walks you through it.